g-C3N4/CoTiO3 S-scheme heterojunction for enhanced visible light hydrogen production through photocatalytic pure water splitting

Photocatalytic hydrogen (H2) production via water splitting in the absence of sacrificial agents is a promising strategy for producing clean and sustainable hydrogen energy from solar energy. However, the realization of a photocatalytic pure water splitting system with desirable efficiency is still a huge challenge. Herein, visible light photocatalytic H2 production from pure water splitting was successfully achieved using a g-C3N4/CoTiO3 S-scheme heterojunction photocatalyst in the absence of sacrificial agents. An optimum hydrogen evolution rate of 118 mu mol center dot h-1 center dot g-1 was reached with the addition of 1.5 wt% CoTiO3. The remarkably promoted hydrogen evolution rate was attributed to the intensified light absorption coupled with the synergistic effect of visible light responsive CoTiO3, the promoted efficiency in charge separation, and the reserved strong redox capacity induced by the S-scheme charge transfer mechanism. This work provides an alternative to visible light-responding oxidation photocatalysts for the construction of S-scheme heterojunctions and high-efficiency photocatalytic systems for pure water splitting. Published by Elsevier B.V. All rights reserved.

Automated summary

In this study, visible light photocatalytic hydrogen production from pure water splitting was achieved using a g-C3N4/CoTiO3 heterojunction photocatalyst, reaching an optimum hydrogen evolution rate of 118 μmol/h·g. The enhanced efficiency was attributed to intensified light absorption, synergistic effect of CoTiO3, improved charge separation efficiency, and strong redox capacity induced by the S-scheme charge transfer mechanism.