K2HPO4-mediated Photocatalytic H_(2)Production over NiCoP/RP Heterojunction

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 H_(2)releasing kinetics than the corresponding single metal phosphides alone.6 wt%NiCoP/RP exhibits an excellent H_(2)evolution activity in 20 vol.%triethanol-amine/water solution under a 300W Xe-lamp irradiation,and the corresponding H_(2)production rate is 1535.6μmol·g^(-1)·h^(-1),which is 7.4,3.2 and 2.6 times higher than those of pure RP,6 wt%Co_(2)P/RP and 6 wt%Ni_(2)P/RP,respectively.In addition,we demonstrate that K_(2)HPO_(4)can further enhance the H_(2)evolution kinetics by inducing a new H^(+)reduction path,when appropriate K_(2)HPO_(4)is introduced into the reaction solution.The H_(2)production rate of 6 wt%NiCoP/RP is boosted from 1535.6 to 2793.9μmol·g^(-1)·h^(-1) due to the easier combination between H^(+)and electrons with the assistance of HPO_(4)^(2-).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 H_(2)evolution efficiency.