A ternary calabash model photocatalyst (Pd/MoP)/CdS for enhancing H2 evolution under visible light irradiation

Noble metal and non-noble metal co-catalysts have their own advantages for improving photocatalytic hydrogen evolution. Here, we report a new composite co-catalyst (Pd/MoP) and a ternary photocatalyst (Pd/MoP)/CdS for hydrogen evolution. The optimum photocatalytic hydrogen evolution of (Pd/MoP)/CdS reaches 943 mu mol/h, which is 2.1 times of MoP/CdS and 4.4 times of Pd/CdS. Transient photocurrent responses, photoluminescence spectroscopies, and surface photovoltage spectroscopies demonstrated the combination of (Pd/MoP) makes highefficiency of charge separation on CdS. Galvanostatic charge/discharge and cyclic voltammetry tests revealed MoP mainly serves as a reservoir to store photo-excited electrons from CdS. Electrochemical impedance spectra and linear sweep voltammetry measures revealed Pd mainly acts as active sites for hydrogen evolution. Most importantly, the functions of each part of ternary photocatalyst for hydrogen evolution have been clarified, and a ternary calabash model photocatalyst for hydrogen evolution is put forward.

Automated summary

The study presented a new composite co-catalyst and a ternary photocatalyst for hydrogen evolution, achieving significant improvement in photocatalytic hydrogen evolution. Experimental results revealed the functions of each part in hydrogen evolution, proposing a ternary photocatalyst model.