a rhpx/g-c 3 no 4 Composite photocatalyst and its preparation method and application

Abstract

The invention belongs to the technical field of nanomaterial synthesis and relates to a RhPx / g-C 3 N 4 Composite photocatalyst and its preparation method and application, in the present invention, utilize simple and rapid electrostatic drive self-assembly method and direct phosphating method x Heterogeneous Nanoparticle Loading on g‑C 3 N 4 surface, constituting different proportions of RhP x / g‑C 3 N 4 The composite photocatalyst system realizes efficient and stable photolysis of water to produce hydrogen under visible light. in g‑C 3 N 4 Ultrathin layer surface modification of RhP x , which not only provides abundant surface active sites, but also increases g‑C 3 N 4 The ability to absorb light and the separation and transport efficiency of carriers can effectively prevent the recombination of photogenerated electron-hole pairs and improve the photocatalytic activity. In addition, RhP x / g‑C 3 N 4 The composite catalyst has high stability and reusability.

Description

technical field

[0001] The invention belongs to the technical field of nanomaterial synthesis and relates to a RhP x / g -C 3 N 4 Composite photocatalyst and its preparation method and application. Background technique

[0002] In recent years, semiconductor photocatalysis technology, as an efficient, safe and environmentally friendly solar energy conversion technology, has received extensive attention. Among them, hydrogen production by photolysis of water is non-toxic, non-polluting, mild reaction conditions and strong stability, and can be reused. Characteristics are considered to be one of the most potential ways to alleviate the global energy crisis. So far, although a large number of photocatalytic materials have been developed and utilized, these catalysts still have defects such as photocatalytic instability, inability to fully utilize solar energy, or toxicity to the environment.

[0003] Graphite carbon nitride (g-C 3 N 4 ) is a non-metallic semiconductor mate...

Examples

Embodiment 1

[0036] Example 1: RhP x / g -C 3 N 4 -1 Preparation of photocatalyst and its photolysis of water to produce hydrogen

[0037] (1) Preparation of ultra-thin g-C 3 N 4 Nanosheets:

[0038] Weigh a certain amount of urea, dry it in an oven at 80°C overnight, then grind it into a powder form and put it into a crucible with a lid. -1 The heating rate was raised to 550°C and calcined for 4h. After naturally cooling down to room temperature, the calcined product was taken out and stirred overnight in an appropriate amount of concentrated nitric acid (pH=1), then washed several times with deionized water until the pH of the filtrate was consistent with that of deionized water, and dried thoroughly in an oven to obtain g-C 3 N 4 .

[0039] Weigh 2g g-C 3 N 4 , from room temperature to 5°C min in the muffle furnace -1 The heating rate was increased to 500 ° C, and calcined for 4 h to obtain ultra-thin g-C 3 N 4 Nanosheets.

[0040] (2) Preparation of RhP x / g -C 3 N 4 -1...

Embodiment 2

[0045] Example 2: RhP x / g -C 3 N 4 -3 Preparation of photocatalyst and its photolysis of water to produce hydrogen

[0046] Step (1) is the same as in Example 1.

[0047] (2) Preparation of RhP x / g -C 3 N 4 -3 Photocatalyst:

[0048] Weigh 0.2g ultra-thin g-C 3 N 4 , dissolved in deionized water, and ultrasonically stirred to obtain a uniformly dispersed suspension. Accurately weigh rhodium triacetylacetonate, metal Rh and ultra-thin g-C 3 The mass ratio of N is 3:100, dissolved in deionized water, at this time the metal Rh is in the ultrathin g-C 3 N 4 With a loading of 3%, rhodium triacetylacetonate solution was added dropwise to the ultrathin g-C 3 N 4 The suspension was stirred by magnetic force for 3h. Then add 0.15 mol / L NaOH solution drop by drop to the suspension, and the molar ratio of metal Rh to sodium hydroxide n(Rh):n(NaOH)=1:2, magnetic stirring for 1h, 80°C oil bath overnight .

[0049] Grind the sample dried in the oil bath to powder, mix it w...

Embodiment 3

[0052] Example 3: RhP x / g -C 3 N 4 -5 Preparation of photocatalyst and its photolysis of water for hydrogen production

[0053] Step (1) is the same as in Example 1.

[0054](2) Preparation of RhP x / g -C 3 N 4 -5 Photocatalyst:

[0055] Weigh 0.2g ultra-thin g-C 3 N 4 , dissolved in deionized water, and ultrasonically stirred to obtain a uniformly dispersed suspension. Accurately weigh rhodium triacetylacetonate, metal Rh and ultra-thin g-C 3 N 4 The mass ratio is 5:100, dissolved in deionized water, at this time the metal Rh is in the ultrathin g-C 3 N 4 With a loading of 5%, rhodium triacetylacetonate solution was added dropwise to the ultrathin g-C 3 N 4 The suspension was stirred by magnetic force for 3h. Then add a certain amount of 0.15mol / L NaOH solution drop by drop to the suspension, and the molar ratio of metal Rh to sodium hydroxide n(Rh):n(NaOH)=1:2, magnetic stirring for 1h, 80℃ oil Bath overnight.

[0056] Grind the sample dried in the oil bath...

technical field

[0001] The invention belongs to the technical field of nanomaterial synthesis and relates to a RhP x / g -C 3 N 4 Composite photocatalyst and its preparation method and application. Background technique

[0002] In recent years, semiconductor photocatalysis technology, as an efficient, safe and environmentally friendly solar energy conversion technology, has received extensive attention. Among them, hydrogen production by photolysis of water is non-toxic, non-polluting, mild reaction conditions and strong stability, and can be reused. Characteristics are considered to be one of the most potential ways to alleviate the global energy crisis. So far, although a large number of photocatalytic materials have been developed and utilized, these catalysts still have defects such as photocatalytic instability, inability to fully utilize solar energy, or toxicity to the environment.

[0003] Graphite carbon nitride (g-C 3 N 4 ) is a non-metallic semiconductor mate...

Examples

Embodiment 1

[0036] Example 1: RhP x / g -C 3 N 4 -1 Preparation of photocatalyst and its photolysis of water to produce hydrogen

[0037] (1) Preparation of ultra-thin g-C 3 N 4 Nanosheets:

[0038] Weigh a certain amount of urea, dry it in an oven at 80°C overnight, then grind it into a powder form and put it into a crucible with a lid. -1 The heating rate was raised to 550°C and calcined for 4h. After naturally cooling down to room temperature, the calcined product was taken out and stirred overnight in an appropriate amount of concentrated nitric acid (pH=1), then washed several times with deionized water until the pH of the filtrate was consistent with that of deionized water, and dried thoroughly in an oven to obtain g-C 3 N 4 .

[0039] Weigh 2g g-C 3 N 4 , from room temperature to 5°C min in the muffle furnace -1 The heating rate was increased to 500 ° C, and calcined for 4 h to obtain ultra-thin g-C 3 N 4 Nanosheets.

[0040] (2) Preparation of RhP x / g -C 3 N 4 -1...

Embodiment 2

[0045] Example 2: RhP x / g -C 3 N 4 -3 Preparation of photocatalyst and its photolysis of water to produce hydrogen

[0046] Step (1) is the same as in Example 1.

[0047] (2) Preparation of RhP x / g -C 3 N 4 -3 Photocatalyst:

[0048] Weigh 0.2g ultra-thin g-C 3 N 4 , dissolved in deionized water, and ultrasonically stirred to obtain a uniformly dispersed suspension. Accurately weigh rhodium triacetylacetonate, metal Rh and ultra-thin g-C 3 The mass ratio of N is 3:100, dissolved in deionized water, at this time the metal Rh is in the ultrathin g-C 3 N 4 With a loading of 3%, rhodium triacetylacetonate solution was added dropwise to the ultrathin g-C 3 N 4 The suspension was stirred by magnetic force for 3h. Then add 0.15 mol / L NaOH solution drop by drop to the suspension, and the molar ratio of metal Rh to sodium hydroxide n(Rh):n(NaOH)=1:2, magnetic stirring for 1h, 80°C oil bath overnight .

[0049] Grind the sample dried in the oil bath to powder, mix it w...

Embodiment 3

[0052] Example 3: RhP x / g -C 3 N 4 -5 Preparation of photocatalyst and its photolysis of water for hydrogen production

[0053] Step (1) is the same as in Example 1.

[0054](2) Preparation of RhP x / g -C 3 N 4 -5 Photocatalyst:

[0055] Weigh 0.2g ultra-thin g-C 3 N 4 , dissolved in deionized water, and ultrasonically stirred to obtain a uniformly dispersed suspension. Accurately weigh rhodium triacetylacetonate, metal Rh and ultra-thin g-C 3 N 4 The mass ratio is 5:100, dissolved in deionized water, at this time the metal Rh is in the ultrathin g-C 3 N 4 With a loading of 5%, rhodium triacetylacetonate solution was added dropwise to the ultrathin g-C 3 N 4 The suspension was stirred by magnetic force for 3h. Then add a certain amount of 0.15mol / L NaOH solution drop by drop to the suspension, and the molar ratio of metal Rh to sodium hydroxide n(Rh):n(NaOH)=1:2, magnetic stirring for 1h, 80℃ oil Bath overnight.

[0056] Grind the sample dried in the oil bath...

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