Urchin-like TiO2/CdS Nanoparticles Forming an S-scheme Heterojunction for Photocatalytic Hydrogen Production and CO2 Reduction

The use of semiconductor nanoparticle heterojunctions for photocatalytic activities is a very attractive strategy. TiO 2 /CdS is widely used in the photocatalytic degradation of pollutants, but there are few reports on photocatalytic hydrogen production and CO 2 reduction. In this work, rod and fishbone CdS nanoparticles were prepared by the hydrothermal method, and S-scheme TiO 2 /CdS nanoparticles with sea urchin morphology were designed. With Na 2 S and Na 2 SO 3 as sacrifice agents, the H 2 yield of TiO 2 /CdS was 1.07 mmol·h –1 ·g –1, and with [Ru(bpy) 3 ]Cl 2 ·6H 2 O as the photosensitizer and TEOA as the sacrifice agent, the rate of CO production from CO 2 reduction was 47.67 μmol·h –1 ·g –1 . The preparation rates of H 2 and CO were 9 times and 13.3 times for TiO 2 nanoparticles and 3.1 times and 1.7 times for fishbone CdS/TiO 2 composite particles, respectively. The electron transfer path and photocatalytic mechanism were deduced by EPR, TRPL, UPS, etc. The results showed that the construction of the S-scheme heterojunction enhanced the photocatalytic performance of the catalyst. We synthesized the S-scheme TiO 2 /CdS nanoparticle heterojunction for the first time and applied it to the photocatalytic production of H 2 and reduction of CO 2 . This work provides an effective reference for designing high-performance inorganic S-scheme heterojunction catalysts.