NiCoP / CdS photocatalyst as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of photocatalysis, and particularly relates to a NiCoP / CdS photocatalyst as well as a preparation method and application thereof. The method comprises the following steps: dissolving Ni (NO3) 2.6 H2O, Co (NO3) 2.6 H2O and C6H12N in water, stirring, and calcining with NaH2PO2.H2O in an N2 atmosphere to obtain NiCoP; dissolving cadmium nitrate and thiourea in ethylenediamine, then adding NiCoP, and mixing under a magnetic stirrer to obtain a precursor solution; and finally, putting into a high-pressure reaction kettle, carrying out heat treatment in a forced air drying oven, and cooling, centrifuging, washing and drying after the heat treatment is finished, so as to obtain the NiCoP / CdS photocatalyst. The catalyst provided by the invention has relatively strong visible light absorption capacity, relatively large specific surface area and efficient photo-induced electron transfer from an interface to NiCoP, and shows a wide application prospect in the field of photocatalytic hydrogen production.

Description

Technical Field

[0001] The present application belongs to the field of photocatalysis technology, and specifically relates to a NiCoP / CdS photocatalyst and its preparation method and application. Background Art

[0002] In view of the increasingly serious problems of global energy shortage and environmental pollution, the exploration of efficient and sustainable renewable energy is crucial to the long-term development of social economy. Hydrogen energy, with its clean, high energy density and sustainable characteristics, has become an important means to meet these challenges. As early as 1972, Japanese scholars Fujishima and Honda first used semiconductor materials as photocatalysts to achieve water decomposition and hydrogen production, marking the beginning of this research field. Ideal photocatalyst semiconductor materials not only need to have suitable energy band positions, but also need to have good absorption capacity for visible light. Although we have made significant progress in photocatalyst research in the past few decades, the development of efficient, economical and durable sunlight-driven photocatalysts is still a very challenging topic and requires continuous investigation and exploration. Summary of the Invention

[0003] The purpose of the present invention is to address the deficiencies of the prior art and provide a NiCoP / CdS photocatalyst and its preparation method and application, specifically adopting the following technical solutions: In a first aspect, the present invention provides a method for preparing a NiCoP / CdS photocatalyst, characterized in that it comprises the following steps: S1, Ni(NO3)2·6H2O, Co(NO3)2·6H2O and C6H 12 N is dissolved in water, stirred, heated, washed, and dried to obtain the precursor NiCo(OH)x; S2, calcining the precursor NiCo(OH)x and NaH2PO2·H2O in a N2 atmosphere to obtain black flower-like NiCoP; S3, dissolving cadmium nitrate and thiourea in ethylenediamine, then adding the NiCoP, and mixing under a magnetic stirrer to obtain a precursor solution; S4. placing the precursor solution in a high-pressure reactor, and then heat-treating the high-pressure reactor in a forced air drying oven. After the heat treatment, cooling, centrifuging, washing, and drying are performed to obtain the NiCoP / CdS photocatalyst.

[0004] As a further preferred embodiment, Ni(NO3)2·6H2O, Co(NO3)2·6H2O and C6H 12 The mass ratio of N is 1.5 mol:2.7 mol:7 mmol.

[0005] As a further preferred embodiment, the usage ratio of the precursor NiCo(OH)x and NaH2PO2·H2O in S2 is 1:1.

[0006] As a further preferred embodiment, the usage ratio of cadmium nitrate, thiourea, ethylenediamine and NiCoP in S3 is 1.54 g:1.14 g:30 mL:24.6 mg-57.4 mg.

[0007] As a further preferred embodiment, the heating temperature in S1 is 90° C.-110° C., and the heating time is 4 h-6 h.

[0008] As a further preferred embodiment, the calcination in S2 is performed at 280°C-350°C, and the calcination time is 1.5 h-2.5 h.

[0009] As a further preferred embodiment, the temperature of the heat treatment in S4 is 150° C.-200° C., and the time of the heat treatment is 20 h-28 h.

[0010] As a further preferred embodiment, the drying temperature in S1 and S4 is both 60°C.

[0011] In a second aspect, the present invention provides a NiCoP / CdS photocatalyst prepared by the above-mentioned preparation method.

[0012] In a third aspect, the present invention provides the use of the above-mentioned NiCoP / CdS photocatalyst in photocatalytic hydrogen production.

[0013] The beneficial effects of the present invention are: This study successfully synthesized rod-shaped CdS using a hydrothermal method and prepared a NiCoP / CdS (NCP / CdS) catalyst using an in situ growth technique. Under visible light irradiation, the NCP / CdS catalyst exhibited excellent hydrogen production performance. Its outstanding advantages include strong visible light absorption, a large specific surface area, and efficient photogenerated electron transfer from HCN to NiCoP at the interface. These properties collectively contribute to a significant increase in hydrogen production rates. Therefore, the NCP / CdS composite material prepared by the preparation method provided by this invention exhibits broad application prospects in the field of photocatalytic hydrogen production. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1Shown is a synthesis process flow chart; among them, (a) the synthesis process route of NiCoP; (b) the synthesis process route of NCP / CdS photocatalyst.

[0016] Figure 2 Shown are the XRD patterns of CdS, NCP, 3%-NCP / CdS, 5%-NCP / CdS, and 7%-NCP / CdS.

[0017] Figure 3 Shown are the SEM, TEM, HRTEM, HADDF, and elemental maps of CdS, NCP, and NCP-CdS. (a) SEM image of CdS; (b) SEM image of NCP; (c) SEM image of NCP / CdS; (df) HRTEM images of NCP / CdS; (g) HADDF image; and (hl) elemental map.

[0018] Figure 4 Shown is the XPS pattern of NCP / CdS.

[0019] Figure 5 Shown are the UV-visible diffuse reflectance spectra and band gap maps; among them, (a) UV-visible diffuse reflectance spectra of different prepared materials; (b) band gap maps of CdS and NCP / CdS.

[0020] Figure 6 Shown are the transient photocurrent response, steady-state photoluminescence spectrum and electrochemical impedance spectroscopy of different materials; among them, (a) transient photocurrent response; (b) steady-state photoluminescence spectrum; (c) electrochemical impedance spectroscopy.

[0021] Figure 7 Shown are the Mott-Schottky curves of different materials at different frequencies.

[0022] Figure 8 Shown are the H2 yield and performance cycle diagrams of different materials; among them, (a) H2 yield diagram; (bc) performance cycle diagram.

[0023] Figure 9 Shown are the XRD comparison and BET test diagram before and after cycling; (a) XRD comparison diagram before and after cycling, (b) BET test diagram.

[0024] Figure 10 Shown is the photocatalytic hydrogen production mechanism diagram of NCP / CdS. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0026] Example 1 A method for preparing a NiCoP / CdS photocatalyst comprises the following steps: (1) Preparation of NiCoP 1.5 mol Ni(NO3)2·6H2O, 2.7 mol Co(NO3)2·6H2O and 7 mmol C6H 12 N4 was added to a beaker containing 50 mL of deionized water and stirred for 3 hours to obtain a clear solution. The clear solution was transferred to a 100 mL stainless steel autoclave lined with polytetrafluoroethylene and heated at 100 ° C for 5 hours. After cooling to room temperature, it was washed three times with ethanol and deionized water and dried at 60 ° C to obtain a green precursor NiCo(OH)x. Subsequently, the precursor NiCo(OH)x and NaH2PO2·H2O were placed in a ceramic boat at a mass ratio of 1:1 and placed in a tube furnace. It was calcined at 300 ° C for 2 hours in a N2 atmosphere to obtain a black flower-like NiCoP (the flow chart is as follows). Figure 1 (as shown in a in the figure); (2) Preparation of NiCoP / CdS (NCP) Accurately weigh cadmium nitrate (1.54 g) and thiourea (1.14 g) into a beaker, add 30 mL of ethylenediamine (EDA) solvent to dissolve, add 57.4 mg of NCP, and continuously mix at room temperature for 45 minutes using a magnetic stirrer to form a uniform precursor solution; the precursor solution is quantitatively transferred to a 100 mL polytetrafluoroethylene-lined autoclave and placed in a forced air drying oven for heat treatment. The program is set to maintain a constant temperature of 180°C for 24 hours to complete the crystallization process; after the reaction is completed, the system is allowed to cool naturally, and the generated yellow precipitate is collected. The product is washed alternately three times with analytical pure ethanol and ultrapure water using centrifugal separation technology to remove impurities. The resulting product is placed in a vacuum drying oven at 60°C for dehydration for 12 hours until constant weight is obtained to obtain NiCoP / CdS photocatalyst (7%-NiCoP / CdS) (the flow chart is as shown in the figure). Figure 1 (as shown in b in the figure).

[0027] Example 2 A method for preparing a NiCoP / CdS photocatalyst, wherein the specific preparation process is similar to that of the embodiment, except that 57.4 mg of NCP in embodiment 1 is replaced with 41 mg of NCP to obtain 5%-NiCoP / CdS.

[0028] Example 3 A method for preparing a NiCoP / CdS photocatalyst, wherein the specific preparation process is similar to that of the embodiment, except that 57.4 mg of NCP in embodiment 1 is replaced with 24.6 mg of NCP to obtain 3%-NiCoP / CdS.

[0029] Comparative Example 1 A method for preparing a CdS catalyst comprises the following steps: Accurately weigh cadmium nitrate (1.54 g) and thiourea (1.14 g) into a beaker, add 30 mL of ethylenediamine (EDA) solvent to dissolve, stir for 45 minutes, transfer the solution into a 100 mL polytetrafluoroethylene-lined autoclave, and place it in a forced air drying oven for heat treatment. The program is set to maintain a constant temperature of 180°C for 24 hours to complete the crystallization process. After the reaction is completed, the system is allowed to cool naturally, and the generated yellow precipitate is collected. It is washed alternately three times with analytical grade ethanol and ultrapure water using centrifugal separation technology to remove impurities. The resulting product is placed in a vacuum drying oven for dehydration at 60°C for 12 hours until constant weight is obtained to obtain CdS.

[0030] Example 4 The prepared materials were characterized and analyzed, and the specific process was as follows: (1) Crystal structure analysis The crystal structure of the prepared photocatalyst was analyzed using X-ray diffraction technology (XRD, Cu Kα radiation), scanning in the range of 10°-70° at a rate of 6° / min.

[0031] The results are as follows Figure 2As shown in the figure, by analyzing the position and intensity of the diffraction peaks, the crystal structure type and purity of the material can be accurately identified. For the diffraction pattern of pure CdS, its main diffraction peaks are located at 24.8°, 26.50°, 28.18°, 36.62°, 43.68°, 47.83°, 52.79°, 54.58°, 58.27°, 66.77°, 70.86° and 75.47°, respectively, which can be attributed to the (100), (002), (101), (102), (110), (103), (201), (004), (202), (203), (211) and (105) crystal planes of CdS (PDF#41-1049). The peaks of NCP at 41.0°, 44.8°, 47.5°, 54.3°, 54.9° and 55.4° match well with the (111), (201), (210), (300), (002) and (211) planes of hexagonal NiCoP (PDF#71-2336), respectively. No redundant diffraction peaks were observed, indicating that both crystals are pure. ◦ A weak NCP characteristic diffraction peak can be observed in the diffraction pattern. This is because the NCP formed by phosphating has poor properties and the characteristic peak intensity is very low. Therefore, the characteristic peak of the co-catalyst NCP is not obvious. These results indicate that the NCP / CdS composite catalyst was successfully prepared.

[0032] (2) Morphology analysis The morphology and structure of the prepared photocatalyst were observed and analyzed in detail using scanning electron microscopy (SEM, model Nova NaSEM450) and transmission electron microscopy (TEM, model FEITalos F200X).

[0033] The results are as follows Figure 3 As shown by Figure 3 (ab) It can be clearly seen that CdS exists in the form of rods while NCP appears in bulk form; Figure 3 (c) shows that the CdS nanorods are tightly bound to the sea urchin structured NCP, which improves the dispersion of CdS and enhances the light absorption of the catalyst. The morphology and structure of the catalyst were further studied by TEM. HRTEM images were obtained at the contact cross section. Figure 3 (df) shows that the CdS surface is in close contact with the NCP. Figure 3 In (f), the crystal plane with a lattice spacing of 0.337 nm is identified as the (022) crystal plane of CdS, while the crystal plane with a lattice spacing of 0.23 nm corresponds to the (111) crystal plane of NCP. Transmission electron microscopy (TEM) analysis shows that there is a close contact interface between CdS and NCP, and this interface property facilitates the efficient transfer of photogenerated carriers. Figure 3(gl) is the HAADF and Mapping image of NAC. It can be found that the above elements are evenly distributed and cross-linked with each other, further proving that the composite material was successfully prepared.

[0034] (3) Element composition and valence The elemental composition and chemical valence state of the prepared catalysts were deeply and thoroughly analyzed using X-ray photoelectron spectroscopy (XPS, model Axis Ultra DLD).

[0035] The results are as follows Figure 4 As shown in the figure, the XPS spectrum obtained by full spectrum scanning shows the characteristic peak positions and relative content information of each element in the sample. In the NCP / CdS composite material, peaks of Cd 3d, S 2p, Ni 2p, Co 2p, and P 2p can be observed. Figure 4 (b) shows that the binding energy of Cd in CdS is 411.26 and 404.55 eV. This indicates that the valence state of Cd in CdS is positive divalent.

[108] . Figure 4 The S 2p XPS spectrum in (c) shows two peaks. 1 / 2 and S 2p 3 / 2 located at 160.9 eV and 162.17 eV, indicating that S in CdS nanoparticles is S 2− exists in the form of

[109] .exist Figure 4 The Ni 2p peak in (d) can be fitted with two peaks at 856.35 and 873.74 eV, and the satellite peaks are located at 860.68 and 880.10 eV. The peaks at 781.31 eV and 790.18 eV in the Co 2p spectrum are close to the peaks of Co element in NiCoP. 1 / 2 and Co 2p 3 / 2 The peaks at 796.72 eV and 787.97 eV in the Co 2p spectrum are assigned to the material formed by partial oxidation of NiCoP exposed to air, and the satellite peaks are located at 787.97 and 801.81 eV. The P 2p spectrum has two peaks at 128.75 and 133.14 eV. The former corresponds to the P in NiCoP. n- , the latter belongs to PO4 3- or P2O5, is due to the partial oxidation of NiCoP caused by exposure to air. The above results are consistent with XRD and TEM, further indicating that NCP and CdS are successfully composited.

[0036] (4) Band gap structure analysis The diffuse reflectance spectra of the samples were tested using an ultraviolet-visible diffuse reflectance spectrometer (UV-vis, Shimadzu UV-2450 model).

[0037] The results are as follows Figure 5 As shown in the figure, it can be seen that the absorption edge of CdS appears at about 509.5 nm, while the absorption edge of 5% NCP / CdS appears at 531.6 nm. The wider visible light absorption range improves the catalyst's ability to absorb light. In addition, compared with CdS, the light capture rate of NCP / CdS in the range of 200-800 nm is significantly improved, which is due to the synergistic effect between NCP and CdS, which is beneficial to the photocatalytic ability. In order to further understand the change in the band gap, [(αhν) n =A(hν-E g )] calculated Figure 5 (b). Where α is the absorption coefficient, a is a constant, h is Planck's constant, E g is the band energy, m is the incident light frequency, and n is equal to 1 (direct-gap semiconductor) or 4 (indirect-gap semiconductor). The calculated band gap values ​​for CdS and 5% NCP / CdS are 2.41 and 2.27 eV, respectively. The band gap value of 5% NCP / CdS is lower than that of CdS because the absorption edge undergoes a red shift, resulting in a smaller band gap. The results show that the loaded NCP enhances the material's light absorption capacity, further confirming its role as a highly efficient co-catalyst, effectively promoting the utilization of visible light.

[0038] (5) Fluorescence analysis The fluorescence emission intensity of the material was observed and analyzed in detail using a fluorescence emission spectrometer (PL, model Hitachi F4500) under 330 nm excitation light.

[0039] as a result Figure 6 b shows the PL intensity of the samples. Lower PL intensity indicates stronger carrier separation and transfer. The 5% NCP / CdS sample has the lowest PL intensity, indicating that the NCP loading helps suppress the recombination efficiency of electrons and holes. This is consistent with the performance results.

[0040] Example 5 The prepared materials were subjected to material performance tests (the NCP / CdS photocatalytic hydrogen production mechanism is shown in the figure). Figure 10 The specific process is as follows: (1) Photocatalytic performance test In performance evaluation, the hydrogen production performance of pure CdS, NiCoP, and NiCoP / CdS was investigated using deionized water as the solvent and triethanolamine as the sacrificial agent. The procedure was as follows: First, 10 mg of the catalyst was evenly dispersed in a quartz tube containing 2 mL of triethanolamine (TEOA) and 10 mL of deionized water. Argon was then continuously purged into the reactor for 30 minutes to completely displace the air inside. A 300-W xenon lamp equipped with a 420 nm filter (λ ≥ 420 nm) was used as the light source. The reaction was continued for 2 hours, and 500 μL of the gaseous product was collected and qualitatively analyzed using a Pana A91 Plus gas chromatograph equipped with a thermal conductivity detector. Sample stability was verified through a cyclic experiment, with argon recirculation after each cycle and 0.5 mL of triethanolamine added every two cycles.

[0041] The results are as follows Figure 8-Figure 9 As shown. The photocatalytic hydrogen production rate of each material under the same test conditions. NCP itself does not show obvious photocatalytic activity due to its low light absorption and high recombination rate of photogenerated electrons and holes, indicating that NCP is not an active photocatalyst. Due to the shortcomings of CdS such as photocorrosion and low efficiency of photogenerated carrier migration, its hydrogen production performance is not high. After loading NCP on CdS, the hydrogen production performance is significantly improved. The hydrogen production rate of CdS loaded with 5% NCP reaches 5.503 nmol / g / h, which is 12.91 times that of pure CdS. It can also be seen in the figure that with the increase of NCP content, the hydrogen evolution activity of NCP / CdS decreases. This is because the excessive loading of NCP inhibits the absorption of light by CdS. On the contrary, when the NCP addition amount is less than 5%, the hydrogen evolution rate increases with the increase of NCP addition. This is because the sea urchin-shaped NCP can provide more active sites for the reaction. In addition, the BET of NCP / CdS and CdS has been tested and calculated to be 22.13 and 15.86 m 2 g −1 ( Figure 9 b). The BET of NCP / CdS is greater than that of CdS nanorods, which proves that the sea urchin-shaped NCP can provide more active sites for the reaction. The material cycle performance diagram is shown in Figure 2. Figure 8 As shown in (bc), during the cycling test, 0.25 ml of sacrificial agent was added to the reaction device after each cycle without changing other conditions. After 9 hours of illumination, only 11.1% of the initial performance was lost, while CdS lost 74.6%. This demonstrates the strong stability of 5% NCP / CdS. XRD characterization of the cycled 5% NCP / CdS was performed. Clearly, there was no significant change in the XRD crystal form and phase before and after the reaction ( Figure 9 a) The above results fully demonstrate that 5% NCP / CdS has excellent stability.

[0042] (2) Electrochemical performance test Materials characterization experiments were conducted using a CHI 660D electrochemical analysis system (Shanghai Chenhua Instruments). The specific preparation process is as follows: Initially, 10.0 mg of sample was accurately weighed and sequentially injected with 100 μL of anhydrous ethanol, 70 μL of ultrapure water, and 30 μL of naphthol solution. The mixture was then transferred to an ultrasonic reactor for 90 minutes of dispersion. A 1 cm × 1 cm FTO conductive glass substrate was selected and ultrasonically cleaned multiple times with anhydrous ethanol. The pretreated sample was then evenly coated and cured at room temperature. Regarding the test system configuration, a standard three-electrode electrochemical test system was used: surface-modified ITO conductive glass (1 cm × 1 cm) as the working electrode, a high-purity platinum wire mesh electrode (surface area 2 cm²) as the counter electrode, and Ag / AgCl (3 mol / L KCl filling solution) as the reference electrode. The entire test process was conducted in a 0.1 mol / L Na₂SO₄ electrolyte system, which was deoxygenated by nitrogen bubbling for 30 minutes to ensure a stable test environment. To characterize the material's carrier separation properties, the transient photocurrent response was recorded by periodically switching the light source on and off under a 300 W xenon lamp to simulate sunlight. Mott-Schottky (MS) curves were measured at three characteristic frequencies: 500 Hz, 1 kHz, and 1.5 kHz.

[0043] The results are as follows Figure 6-Figure 7 As shown, Figure 6 (a) shows the transient photocurrent test results of the materials. It can be clearly seen that the photocurrent density of 5% NCP / CdS is higher than that of CdS; the higher photocurrent density indicates better separation of photogenerated electrons and holes. Figure 6 (b) is the PL intensity graph of the sample. Lower PL intensity indicates stronger carrier separation and transfer. The PL intensity of the 5% NCP / CdS sample is the lowest, indicating that the loading of NCP is beneficial to suppress the recombination efficiency of electrons and holes. This is consistent with the results shown in the performance. Charge transfer efficiency is also one of the important factors affecting photocatalytic performance, so EIS studies were performed on the material, such as Figure 6 (c) The results show that 5% NCP / CdS has the smallest arc radius, so its resistance is lower than that of other materials. This indicates that the loading of 5% NCP / CdS material greatly enhances the electron-hole separation efficiency.

[0044] In order to determine the conduction band (CB) and valence band (VB) positions of the material, Mott-Schottky (MS) test was performed and the results were Figure 7(ab). The MS curves of NCP and CdS are both positive, indicating that they are both n-type semiconductors. After the introduction of NCP into CdS, the negative shift of the flat band potential reveals the strong reducing ability of photogenerated electrons, which is conducive to accelerating the transfer of conduction band electrons. The flat band potential of CdS obtained from the MS curve can be regarded as the ECB of CdS. Therefore, the E of CdS CB is about -0.79 eV. The calculated E of CdS is VB 1.62 eV.

[0045] In summary, the present invention successfully synthesized rod-shaped CdS using a hydrothermal method and prepared the NCP / CdS catalyst using an in-situ growth technique. Under visible light irradiation, the NCP / CdS catalyst exhibited excellent hydrogen production performance. Its outstanding advantages include: strong visible light absorption capacity, large specific surface area, and efficient photogenerated electron transfer from HCN to NiCoP at the interface. These characteristics jointly promote a significant increase in the hydrogen production rate. With the help of this economical and efficient preparation method, NCP / CdS composite materials show broad application prospects in the field of photocatalytic hydrogen production.

[0046] The embodiments of the present application are described above in conjunction with the accompanying drawings. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the core idea of ​​the present application, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present application and the claims, all of which are within the protection of the present application.

Claims

1. A method for preparing a NiCoP / CdS photocatalyst, characterized in that: The following steps are involved: S1, Ni(NO3)2·6H2O, Co(NO3)2·6H2O and C6H 12 N is dissolved in water, stirred, heated, washed, and dried to obtain the precursor NiCo(OH) x ; S2, the precursor NiCo(OH) x and NaH2PO2·H2O in N2 atmosphere to obtain black flower-like NiCoP; S3, dissolving cadmium nitrate and thiourea in ethylenediamine, then adding the NiCoP, and mixing under a magnetic stirrer to obtain a precursor solution; S4. placing the precursor solution in a high-pressure reactor, and then heat-treating the high-pressure reactor in a forced air drying oven. After the heat treatment, cooling, centrifuging, washing, and drying are performed to obtain the NiCoP / CdS photocatalyst.

2. The preparation method according to claim 1, characterized in that Ni(NO3)2·6H2O, Co(NO3)2·6H2O and C6H 12 The usage ratio of N is 1.5 mol:2.7 mol:7 mmol.

3. The preparation method according to claim 2, characterized in that Precursor NiCo(OH) in S2 x The mass ratio of NaH2PO2·H2O is 1:

1.

4. The preparation method according to claim 3, characterized in that The usage ratio of cadmium nitrate, thiourea, ethylenediamine and NiCoP in S3 is 1.54 g:1.14 g:30 mL:24.6 mg-57.4 mg.

5. The preparation method according to claim 1, characterized in that The heating temperature in S1 is 90°C-110°C, and the heating time is 4 h-6 h.

6. The preparation method according to claim 1, characterized in that The calcination temperature in S2 is 280-350°C, and the calcination time is 1.5 h-2.5 h.

7. The preparation method according to claim 1, characterized in that The heat treatment temperature in S4 is 150°C-200°C, and the heat treatment time is 20 h-28 h.

8. The preparation method according to claim 1, characterized in that The drying temperature in both S1 and S4 was 60°C.

9. A NiCoP / CdS photocatalyst, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the NiCoP / CdS photocatalyst according to claim 9 in photocatalytic hydrogen production.

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