Nonmetal BCN-gC3N4 Van der Waals heterojunction photocatalyst, and preparation method and application thereof

Abstract

The invention relates to a preparation method and an application of a nonmetal BCN / g-C3N4 Van der Waals heterojunction photocatalyst. A convenient and efficient calcination synthesis technology is utilized to perform secondary calcination on a BCN nanosheet obtained by one-step calcination and g-C3N4, so that the BCN nanosheet is compounded on the surface of the g-C3N4 to form the BCN / g-C3N4 Van der Waals heterojunction photocatalyst with a stable structure; and the photoatalyst achieves stable and efficient hydrogen production by photolysis of water under visible light. The BCN / g-C3N4 Van derWaals heterojunction photocatalyst prepared in the invention has high stability and reusability; and additionally, the method has the advantages of simplicity, low cost, greenness, non-toxicity, veryhigh practical values and very high application prospect.

Description

technical field

[0001] The invention belongs to the field of nanomaterial synthesis and relates to non-metallic BCN / g-C 3 N 4 Van der Waals heterojunction photocatalyst and its preparation method and application. Background technique

[0002] At present, renewable solar energy-driven photolysis of water hydrogen production technology is widely used in the field of clean energy development due to its cheap energy source, non-toxic, non-polluting, mild reaction conditions, strong stability and reusable characteristics. A promising green and sustainable hydrogen production technology.

[0003] Among various photoresponsive materials that can be used as photocatalysts, semiconductor photocatalysts are the most explored and developed. There are many kinds of semiconductor materials, such as titanium dioxide, zinc oxide, cadmium sulfide, ferric oxide and other transition metal oxides and sulfides, among which titanium dioxide has strong chemical properties, non-toxic, strong co...

Examples

Embodiment 1

[0032] Example 1: Preparation of BCN / g-C 3 N 4 -0.1% van der Waals heterojunction photocatalyst and its photocatalytic hydrogen production

[0033] (1) Preparation of g-C 3 N 4

[0034] Weigh 100g of urea, put it in a drying oven, bake it at 80°C for 12h, take it out, grind it to powder, put it into a crucible, cover it, and put it into a muffle furnace for calcination at 550°C for 4h with a heating rate of 2.5°C / min. After natural cooling, the calcined product was taken out and put into 300mL of 1.5M nitric acid solution, and stirred for 12h. Then carry out washing and suction filtration, wash with deionized water until the pH value of the filtrate is consistent with that of deionized water, and finally put it into a drying oven for drying at 80°C.

[0035] (2) Preparation of BCN nanosheets

[0036] Weigh 2g of boron oxide, 4g of urea, and 0.6g of glucose, put them into a quartz mortar, grind them finely, mix well, then put the mixture into a porcelain boat, cover it, p...

Embodiment 2

[0041] Example 2: BCN / g-C 3 N 4 Preparation of -0.3% Van der Waals Heterojunction Photocatalyst and Photocatalytic Hydrogen Production

[0042] Steps (1)-(2) are the same as in Example 2.

[0043] (3) Preparation of BCN / g-C 3 N 4 -0.3% van der Waals heterojunction photocatalyst

[0044] Weigh 1 g of g-C prepared in step (1) 3 N 4 With 0.003g of BCN nanosheets, ground in a quartz mortar, transferred to a porcelain boat, put the porcelain boat into a tube furnace, and heated in N 2 Heated to 500°C at a heating rate of 5°C / min under air protection, and calcined for 4 hours to obtain BCN / g-C 3 N 4 -0.3% photocatalyst.

[0045] (4) BCN / g-C 3 N 4 -0.3% van der Waals heterojunction photocatalyst for photocatalytic hydrogen production

[0046] The photocatalytic reaction was carried out in a closed reaction system with a total volume of about 250mL, and 50mg BCN / g-C 3 N 4 -0.3% catalyst was uniformly dispersed in 100mL 20vol% pH 11.4 TEOA aqueous solution, then 3% H 2 P...

Embodiment 3

[0047] Example 3: BCN / g-C 3 N 4 Preparation of -0.5% van der Waals heterojunction photocatalyst and photocatalytic hydrogen production

[0048] Steps (1)-(2) are the same as in Example 2.

[0049] (3) Preparation of BCN / g-C 3 N 4 -0.5% van der Waals heterojunction photocatalyst

[0050] Weigh 1 g of g-C prepared in step (1) 3 N 4 With 0.005g of BCN nanosheets, ground in a quartz mortar, transferred to a porcelain boat, put the porcelain boat into a tube furnace, and heated in N 2 Heated to 500°C at a heating rate of 5°C / min under air protection, and calcined for 4 hours to obtain BCN / g-C 3 N 4 -0.5% photocatalyst.

[0051] (4) BCN / g-C 3 N 4 -0.5% van der Waals heterojunction photocatalyst for photocatalytic hydrogen production

[0052] The photocatalytic reaction was carried out in a closed reaction system with a total volume of about 250mL, and 50mgBCN / g-C 3 N 4 -0.5% catalyst was uniformly dispersed in 100mL 20vol% pH 11.4 TEOA aqueous solution, then 3% H 2 Pt...

technical field

[0001] The invention belongs to the field of nanomaterial synthesis and relates to non-metallic BCN / g-C 3 N 4 Van der Waals heterojunction photocatalyst and its preparation method and application. Background technique

[0002] At present, renewable solar energy-driven photolysis of water hydrogen production technology is widely used in the field of clean energy development due to its cheap energy source, non-toxic, non-polluting, mild reaction conditions, strong stability and reusable characteristics. A promising green and sustainable hydrogen production technology.

[0003] Among various photoresponsive materials that can be used as photocatalysts, semiconductor photocatalysts are the most explored and developed. There are many kinds of semiconductor materials, such as titanium dioxide, zinc oxide, cadmium sulfide, ferric oxide and other transition metal oxides and sulfides, among which titanium dioxide has strong chemical properties, non-toxic, strong co...

Examples

Embodiment 1

[0032] Example 1: Preparation of BCN / g-C 3 N 4 -0.1% van der Waals heterojunction photocatalyst and its photocatalytic hydrogen production

[0033] (1) Preparation of g-C 3 N 4

[0034] Weigh 100g of urea, put it in a drying oven, bake it at 80°C for 12h, take it out, grind it to powder, put it into a crucible, cover it, and put it into a muffle furnace for calcination at 550°C for 4h with a heating rate of 2.5°C / min. After natural cooling, the calcined product was taken out and put into 300mL of 1.5M nitric acid solution, and stirred for 12h. Then carry out washing and suction filtration, wash with deionized water until the pH value of the filtrate is consistent with that of deionized water, and finally put it into a drying oven for drying at 80°C.

[0035] (2) Preparation of BCN nanosheets

[0036] Weigh 2g of boron oxide, 4g of urea, and 0.6g of glucose, put them into a quartz mortar, grind them finely, mix well, then put the mixture into a porcelain boat, cover it, p...

Embodiment 2

[0041] Example 2: BCN / g-C 3 N 4 Preparation of -0.3% Van der Waals Heterojunction Photocatalyst and Photocatalytic Hydrogen Production

[0042] Steps (1)-(2) are the same as in Example 2.

[0043] (3) Preparation of BCN / g-C 3 N 4 -0.3% van der Waals heterojunction photocatalyst

[0044] Weigh 1 g of g-C prepared in step (1) 3 N 4 With 0.003g of BCN nanosheets, ground in a quartz mortar, transferred to a porcelain boat, put the porcelain boat into a tube furnace, and heated in N 2 Heated to 500°C at a heating rate of 5°C / min under air protection, and calcined for 4 hours to obtain BCN / g-C 3 N 4 -0.3% photocatalyst.

[0045] (4) BCN / g-C 3 N 4 -0.3% van der Waals heterojunction photocatalyst for photocatalytic hydrogen production

[0046] The photocatalytic reaction was carried out in a closed reaction system with a total volume of about 250mL, and 50mg BCN / g-C 3 N 4 -0.3% catalyst was uniformly dispersed in 100mL 20vol% pH 11.4 TEOA aqueous solution, then 3% H 2 P...

Embodiment 3

[0047] Example 3: BCN / g-C 3 N 4 Preparation of -0.5% van der Waals heterojunction photocatalyst and photocatalytic hydrogen production

[0048] Steps (1)-(2) are the same as in Example 2.

[0049] (3) Preparation of BCN / g-C 3 N 4 -0.5% van der Waals heterojunction photocatalyst

[0050] Weigh 1 g of g-C prepared in step (1) 3 N 4 With 0.005g of BCN nanosheets, ground in a quartz mortar, transferred to a porcelain boat, put the porcelain boat into a tube furnace, and heated in N 2 Heated to 500°C at a heating rate of 5°C / min under air protection, and calcined for 4 hours to obtain BCN / g-C 3 N 4 -0.5% photocatalyst.

[0051] (4) BCN / g-C 3 N 4 -0.5% van der Waals heterojunction photocatalyst for photocatalytic hydrogen production

[0052] The photocatalytic reaction was carried out in a closed reaction system with a total volume of about 250mL, and 50mgBCN / g-C 3 N 4 -0.5% catalyst was uniformly dispersed in 100mL 20vol% pH 11.4 TEOA aqueous solution, then 3% H 2 Pt...

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