K2HPO4-mediated Photocatalytic H2 Production over NiCoP/RP Heterojunction

• Published in: Jiégòu huàxué Vol. 41; no. 6; pp. 2206062 - 2206068
• Main Authors: Huang, Junfeng, Li, Chenyang, Hu, Xiaoyun, Fan, Jun, Zhao, Binran, Liu, Enzhou
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 23.06.2022; School of Chemical Engineering/Xi'an Key Laboratory of Special Energy Materials,Northwest University,Xi'an 710069,China%School of Physics,Northwest University,Xi'an 710069,China
• Subjects: bimetallic cocatalyst; hydrogen; K2HPO4; photocatalysis; red phosphorus; bimetallic cocatalyst; K2HPO4; hydrogen; photocatalysis; red phosphorus
• ISSN: 0254-5861
• DOI: 10.14102/j.cnki.0254-5861.2021-0055

In this work, bimetallic NiCoP nanoparticles (NPs) were firstly prepared by a solvothermal method using red phosphorus (RP) as P source, and it was combined with RP nanosheets via a physical grinding process. Investigation indicates that NiCoP has better charge transfer ability and faster H2 releasing kinetics than the corresponding single metal phosphides alone. 6 wt% NiCoP/RP exhibits an excellent H2 evolution activity in 20 vol.% triethanol-amine/water solution under a 300W Xe-lamp irradiation, and the corresponding H2 production rate is 1535.6 μmol•g−1•h−1, which is 7.4, 3.2 and 2.6 times higher than those of pure RP, 6 wt% Co2P/RP and 6 wt% Ni2P/RP, respectively. In addition, we demonstrate that K2HPO4 can further enhance the H2 evolution kinetics by inducing a new H+ reduction path, when appropriate K2HPO4 is introduced into the reaction solution. The H2 production rate of 6 wt% NiCoP/RP is boosted from 1535.6 to 2793.9 μmol•g−1•h−1 due to the easier combination between H+ and electrons with the assistance of HPO42-. It is 13.4 times higher than that of pure RP. This work demonstrates that bimetallic phosphides with suitable electrolytes can greatly enhance the photocatalytic H2 evolution efficiency. NiCoP is employed to facilitate carrier migration and reduce H2 evolution overpotential of red phosphorus (RP), resulting in a H2 production rate of 1535.6 μmol•g−1•h−1 over 6% NiCoP/RP. The H2 evolution kinetics further increases to 2793.9 μmol•g−1•h−1 by inducing a new H+ reduction path after adding appropriate K2HPO4. [Display omitted]