Preparation of Ru / moo2-mo2n heterojunction / n-doped c and its electrocatalytic application

Abstract

The application relates to preparation of a Ru / MoO2-Mo2N heterojunction / N-doped C and electrocatalytic application thereof, in particular to a method for preparing Ru / MoO2-Mo2N heterojunction / N-doped C by mixing, drying and then grinding h-MoO3 microrods, tris(hydroxymethyl)aminomethane, dopamine hydrochloride and RuCl3, and then performing hot reaction with melamine; and application of the Ru / MoO2-Mo2N heterojunction / N-doped C in an electrocatalytic reaction.

Description

Technical Field

[0001] This invention relates to the preparation of Ru / MoO2-Mo2N heterojunction / N-doped C and its electrocatalytic application, belonging to the field of materials preparation and application. Background Technology

[0002] Alleviating environmental pollution and energy crises, and seeking renewable energy sources, is a development trend for human society. Hydrogen combustion produces only water, making it a pollution-free and renewable energy source. Currently, hydrogen production mainly relies on the decomposition of fossil fuels; therefore, developing new energy technologies for hydrogen production is a key research direction. With the rapid development of science and technology, electrocatalytic water splitting for hydrogen production has become an effective means to improve water splitting efficiency in recent years.

[0003] Mo-based materials have attracted considerable research interest due to their unique physicochemical properties. By employing techniques such as heteroatom doping, crystal phase modulation, and morphology-controlled synthesis, the electronic structure of Mo-based materials can be altered, thereby enhancing their electrocatalytic activity. For example, Li et al. hydrothermally synthesized α-MoO3 nanoribbons using MoO3 powder and H2O2. They then mixed the α-MoO3 nanoribbons with Fe(NO3)3·9H2O, using NaH2PO2·H2O as the phosphorus source, and thermally decomposed them at 350℃ for 2 hours under an inert atmosphere to prepare P-MoO2-Fe3O4 nanoribbons. When applied to electrocatalytic water splitting, the current density reached 10 mA / cm² at a voltage of 1.72 V. 2 (Fuel, 2023, 332, 126250). Wang et al. dispersed MoO3 in oleic acid and S powder in oleylamine. Both were dried separately, and the two precursors were mixed and thermally decomposed at high temperature to obtain a MoS2-MoO2 complex. This complex was applied to the electrocatalytic hydrogen evolution reaction, and the initial voltage was 210 mV in 0.5 M H2SO4 electrolyte (Ceramics International, 2017, 43, S621-S627). Wu et al. utilized (NH4)6Mo7O 24 Mo7O was synthesized from 4H2O, aniline, HCl, etc. 18-(C6H5NH)6 hybrid material was calcined at 700℃ in an inert atmosphere for 3 h to obtain N-MoO2-Mo2C hollow nanotubes. Pd loading was then achieved to obtain Pd / N-MoO2-Mo2C, which exhibits highly efficient electrocatalytic oxygen reduction with a half-wave potential of 0.9 V (Materials Today Chemistry, 2022, 24, 100799). Huang et al. obtained MoO2 / CP by calcining MoO3 and carbon cloth at 750℃ for 2 h, and then electrodeposited it with Ni(NO3)2 solution to obtain MoO2@Ni. Using NaH2PO2·H2O as the P source, phosphating yielded MoO2@Ni2P / CP, which showed an electrocatalytic activity of 57 mV reaching 10 mA / cm² in alkaline electrolyte. 2 (Journal of Colloid and Interface Science, 2022, 616, 210-220).

[0004] Hydrogen production through water splitting, converting electrical energy into hydrogen energy, is an important pathway to improve energy efficiency and achieve green catalysis. Constructing a Ru / MoO2-Mo2N heterojunction / N-doped C effectively reduces the overpotential of electrocatalytic water splitting, yielding a highly efficient and stable catalyst, which provides guidance for current energy development. Summary of the Invention:

[0005] This invention aims to provide the preparation of Ru / MoO2-Mo2N heterojunctions / N-doped C and their electrocatalytic applications.

[0006] Based on the above objectives, the technical solution involved in this invention is as follows:

[0007] (1) Preparation of Ru / MoO2-Mo2N heterojunction / N-doped C: 0.5-1.4g α-MoO3 particles were mixed with 11mL H2O2 and 4-6g NaNO3, and then hydrothermally heated at 150-180℃ for 12h to obtain h-MoO3 microrods with a diameter of 1.5-4μm (JCPDS#21-0569); 28mg-50mg h-MoO3 microrods, 110-130mg tris(hydroxymethyl)aminomethane, and 48-66mg dopamine hydrochloride were dispersed in 55mL ethanol and 55mL water, dried, and then mixed with 142-168

[0008] Mix 1 mg of melamine and 30-60 mg of RuCl3, place in a tube furnace, and heat at 520-630℃ for 0.5-1 minute in an Ar atmosphere.

[0009] h, MoO2-Mo2N heterostructure nanosheets coated and encapsulated with N-doped C are obtained, with Ru loaded on the N-doped C, i.e., the Ru / MoO2-Mo2N heterojunction / N-doped C is prepared. In the above preparation method, the MoO2 crystal phase is classified under standard card JCPDS#32-0671, and the Mo2N crystal phase is classified under standard card JCPDS#25-1366.

[0010] (2) Application of Ru / MoO2-Mo2N heterojunction / N-doped C prepared by the above preparation method in electrocatalytic reaction; when the KOH concentration is 1 mol / L and the voltage is 90-120 mV, the current density of the electrocatalytic hydrogen evolution reaction is 10 mA / cm². 2 .

[0011] The present invention has the following advantages:

[0012] 1) Using h-MoO3 microrods, tris(hydroxymethyl)aminomethane, dopamine hydrochloride, and RuCl3 as raw materials, a Ru / MoO2-Mo2N heterojunction / N-doped C was constructed, and a new synthetic route for Ru / MoO2-Mo2N heterojunction / N-doped C was developed.

[0013] 2) The Ru / MoO2-Mo2N heterojunction / N-doped C exhibits good performance in the electrocatalytic hydrogen evolution reaction. Attached image description:

[0014] Figure 1 The structure is characterized by SEM of h-MoO3 microrods; Figure 2 The results are XRD characterizations of Ru / MoO2-Mo2N heterojunction / N-doped C. Detailed Implementation

[0015] The following examples are used to further illustrate the present invention, but are not intended to limit the invention.

[0016] Example 1

[0017] 0.5 g of α-MoO3 particles were mixed with 11 mL of H2O2 and 4 g of NaNO3 and hydrothermally heated at 150 °C for 12 h to obtain h-MoO3 microrods with a diameter of 1.5-4 μm (JCPDS#21-0569). 28 mg of h-MoO3 microrods, 110 mg of tris(hydroxymethyl)aminomethane, and 48 mg of dopamine hydrochloride were dispersed in 55 mL of ethanol and 55 mL of water. After drying, the mixture was mixed with 142 mg of melamine and 30 mg of RuCl3 and placed in a tube furnace. The mixture was heated at 520 °C for 0.5 h in an Ar atmosphere to obtain N-doped C-encapsulated MoO2-Mo2N heterostructure nanosheets with Ru loaded on the N-doped C, i.e., the preparation of Ru / MoO2-Mo2N heterojunction / N-doped C. The above preparation method describes a MoO2 crystal phase classified under standard card JCPDS#32-0671 and a Mo2N crystal phase classified under standard card JCPDS#25-1366. When the Ru / MoO2-Mo2N heterojunction / N-doped C is used, at a KOH concentration of 1 mol / L and a voltage of 90 mV, the electrocatalytic hydrogen evolution reaction current density is 10 mA / cm². 2 .

[0018] Example 2

[0019] 1.4 g of α-MoO3 particles were mixed with 11 mL of H2O2 and 6 g of NaNO3 and hydrothermally heated at 180 °C for 12 h to obtain h-MoO3 microrods with a diameter of 1.5-4 μm (JCPDS#21-0569). 50 mg of h-MoO3 microrods, 130 mg of tris(hydroxymethyl)aminomethane, and 66 mg of dopamine hydrochloride were dispersed in 55 mL of ethanol and 55 mL of water. After drying, the mixture was mixed with 168 mg of melamine and 60 mg of RuCl3 and placed in a tube furnace. The mixture was heated at 630 °C for 1 h in an Ar atmosphere to obtain N-doped C-encapsulated MoO2-Mo2N heterostructure nanosheets with Ru loaded on the N-doped C, i.e., the preparation of Ru / MoO2-Mo2N heterojunction / N-doped C. The above preparation method describes a MoO2 crystal phase classified under standard card JCPDS#32-0671 and a Mo2N crystal phase classified under standard card JCPDS#25-1366. When the Ru / MoO2-Mo2N heterojunction / N-doped C is used, at a KOH concentration of 1 mol / L and a voltage of 120 mV, the electrocatalytic hydrogen evolution reaction current density is 10 mA / cm². 2 .

[0020] Example 3

[0021] 1 g of α-MoO3 particles were mixed with 11 mL of H2O2 and 5 g of NaNO3 and then hydrothermally heated at 180 °C for 12 h to obtain h-MoO3 microrods with a diameter of 1.5-4 μm (JCPDS#21-0569). 40 mg of h-MoO3 microrods, 120 mg of tris(hydroxymethyl)aminomethane, and 55 mg of dopamine hydrochloride were dispersed in 55 mL of ethanol and 55 mL of water. After drying, the mixture was mixed with 160 mg of melamine and 40 mg of RuCl3 and placed in a tube furnace. The mixture was heated at 550 °C for 1 h in an Ar atmosphere to obtain N-doped C-encapsulated MoO2-Mo2N heterostructure nanosheets with Ru loaded on the N-doped C, i.e., the preparation of Ru / MoO2-Mo2N heterojunction / N-doped C. The above preparation method describes a MoO2 crystal phase classified under standard card JCPDS#32-0671 and a Mo2N crystal phase classified under standard card JCPDS#25-1366. When the Ru / MoO2-Mo2N heterojunction / N-doped C is used, at a KOH concentration of 1 mol / L and a voltage of 110 mV, the electrocatalytic hydrogen evolution reaction current density is 10 mA / cm². 2 .

Claims

1. A method for preparing Ru / MoO2-Mo2N heterojunction / N-doped C, characterized in that, The method comprises the following steps: After mixing 0.5-1.4 g α-MoO3 particles, 11 mL H2O2 and 4-6 g NaNO3, hydrothermal treatment is carried out at 150-180 ℃ for 12 h to obtain h-MoO3 microrods with a diameter of 1.5-4 μm, and the crystal phase of the h-MoO3 microrods belongs to standard card JCPDS #21-0569; 28 mg-50 mg h-MoO3 microrods, 110-130 mg tris(hydroxymethyl)aminomethane, 48-66 mg dopamine hydrochloride are dispersed into 55 mL ethanol and 55 mL water, and after drying, they are mixed with 142-168 mg melamine and 30-60 mg RuCl3, and then placed into a tube furnace and heated at 520-630 ℃ for 0.5-1 h in an Ar atmosphere to obtain Ru / MoO2-Mo2N heterojunction / N-doped C; in the Ru / MoO2-Mo2N heterojunction / N-doped C, N-doped C encapsulates MoO2-Mo2N heterostructure nanosheets, and Ru is loaded on the N-doped C, and the MoO2 crystal phase belongs to standard card JCPDS #32-0671, and the Mo2N crystal phase belongs to standard card JCPDS #25-1366.

2. The application of Ru / MoO2-Mo2N heterojunction / N-doped C prepared by the preparation method of claim 1 in an electrocatalytic reaction; when the concentration of KOH is 1 mol / L and the voltage is 90-120 mV, the electrocatalytic hydrogen evolution reaction current density is 10 mA / cm 2 .

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