TiO2/BiOBr 2D-2D heterostructure via in-situ approach for enhanced visible-light photocatalytic N2 fixation

ACS Sustainable Chem. Eng.

Gan

et al. 2023

One-pot synthesis of urea [(NH 2 ) 2 CO] from easily available small molecules, that is, N 2 , CO 2 , and H 2 O, is an extremely attractive but very challenging reaction. 2D-CdS@3D-BiOBr composites with S-scheme heterojunctions are constructed via a facile hydrothermal technique followed by a self-assembly method and shown to be an excellent photocatalyst enabling the reduction of N 2 and CO 2 with H 2 O to (NH 2 ) 2 CO under visible light. The optimal 40%2D-CdS@3D-BiOBr sample shows up to 15 μmol•g −1 •h −1 total yield of NH 3 and (NH 2 ) 2 CO, of which (NH 2 ) 2 CO accounts for 54%. The apparent quantum efficiency (AQE) is 3.93% for urea production. On the photocatalyst, urea is speculated to form by two possible chemical routes. One is direct photocatalytic synthesis. Both N 2 and CO 2 molecules are activated by the Cd 2+ ion of 2D-CdS and the oxygen defect of 3D-BiOBr at the edges of the heterojunction interface of 2D-CdS/3D-BiOBr, respectively. *HNCONH* is the key intermediate of the formation of (NH 2 ) 2 CO molecules. The other is indirect synthesis by photocatalysis and then thermocatalysis. N 2 is reduced into NH 3 and CO 2 is reduced into CO on 2D-CdS by the photogenerated electrons and protons, and then the formed NH 3 reacts with the reactant CO 2 or the product CO to form (NH 2 ) 2 CO by thermocatalysis on 2D-CdS. The former is dominant for urea synthesis. The work confirms that urea could be synthesized photocatalytically from cheap N 2 , CO 2 , and H 2 O under visible light. A composite heterojunction semiconductor could be a prospective photocatalyst appropriate for the complex reaction.

Section: Introductionmentioning

confidence: 99%

Photocatalytic Coreduction of N₂ and CO₂ with H₂O to (NH₂)₂CO on 2D-CdS/3D-BiOBr

ACS Sustainable Chem. Eng.

Gan

et al. 2023

“…Wang et al prepared TiO 2 /BiOBr catalysts with the p–n heterojunction structure by the in situ growth method, which exhibited excellent photocatalytic nitrogen fixation activity and good cycling stability. Especially, the 15% TiO 2 /BiOBr heterojunction catalysts showed a maximum NH 3 yield of 1.43 mmol g –1 h –1 , about 4 times more than that of pure BiOBr . Other recently reported examples of p–n heterojunctions for photocatalytic nitrogen fixation include Ni 3 V 2 O 8 /g-C 3 N 4 , B/g-C 3 N 4 , NiO/KNbO 3 , Cu 2 O/CN, etc.…”

Section: Construction Of the Heterojunctionmentioning

confidence: 99%

Advanced Strategies for Improving the Photocatalytic Nitrogen Fixation Performance: A Short Review

Liang

et al. 2022

Energy Fuels

Self Cite

As an indispensable energy source, ammonia plays a significant role in industrial and agricultural production. Given that the current ammonia production is still dominated by the energy-intensive and high-carbon-footprint Haber–Bosch process, photocatalysts for nitrogen reduction represent a low-energy-consuming and sustainable approach to generate ammonia, which have received extensive attention and research. However, photocatalytic nitrogen fixation materials have limitations, such as the difficulty in N2 adsorption and activation and the recombination of photogenerated carriers. It is still a serious challenge to improve the photocatalytic nitrogen fixation performance to realize its industrial application. It is crucial to master and explore the strategies for improving the performance of photocatalysts. Therefore, this paper reviews the traditional and emerging strategies for improving the performance of photocatalytic nitrogen fixation and briefly prospects the existing challenges and future opportunities. This review is expected to provide momentous breakthroughs on photocatalysts for artificial nitrogen fixation in the next stage.

“…Researchers have made considerable effort to narrow the band gap for TiO 2 and improve the interfacial carrier transport. 31–36…”

Section: Introductionmentioning

confidence: 99%

“…Researchers have made considerable effort to narrow the band gap for TiO 2 and improve the interfacial carrier transport. [31][32][33][34][35][36] Therefore, in order to increase the photocatalytic activity of TiO 2 , particularly in the visible region, and hinder electron-hole recombination reactions, many studies have investigated the combination of TiO 2 with plasmonic NPs, such as Au, Pd and Pt NPs. [37][38][39][40][41] As we all know, precious metals not only greatly absorb visible light but also transfer hot electrons into the neighboring TiO 2 matrix, then induce photocatalytic activity under visible light, for example, Au NPs.…”

Section: Introductionmentioning

confidence: 99%

The order of loading affects photocatalytic nitrogen fixation activity of the ternary composites of PdO/Au–TiO₂

Liu

et al. 2023

New J. Chem.