Rational design of H2 production sites for achieving photoconversion of CO2 with H2O into widely adjustable syngas and highly effective H2 evolution

Abstract

The photoconversion of CO2 with H2O into widely tunable syngas (CO and H2) or pure H2 production is regarded as a promising strategy to mitigate escalating energy shortages and climate change. Herein, anchoring the H2 production sites onto the surface of CdIn2S4 (CIS) with a nanoscale hollow sphere allows for the photoconversion of CO2 into syngas and water splitting to H2. The CO/H2 ratio can be realized in a remarkably wide range from 1:0.38–1:3.76. The optimized CIS/Co-PBA/NaY-5 hybrid exhibits superior photocatalytic syngas evolution up to 1458.48 μmol·g−1·h−1 (H2/CO, 1152.29/306.19 μmol·g−1·h−1), and the H2 evolution rate increases by 431.70 % compared with CIS. The CIS/Co-PBA/NaY-5 hybrid exhibited not only superior H2 evolution but also recyclability. The experimental, energy-dispersive X-ray spectroscopy, and electron spin resonance results indicate that the Co sites serve as H2 production sites and promote the H2 evolution reaction. In addition, the construction of a p-n heterojunction with a special micromorphology is beneficial for the separation/transfer of carriers.