Highly stable and durable ZnIn2S4 nanosheets wrapped oxygen deficient blue TiO2(B) catalyst for selective CO2 photoreduction into CO and CH4.

Designed hexagonal ZnIn 2 S 4 nanosheets wrapped oxygen deficient blue TiO 2 (B) catalyst for highly stable and selective CO 2 Photoreduction into CO and CH 4. The advanced photoactivity is attributed due to improved CO 2 absorption capacity, electron mobility, and visible light accessibility, resulting in effective charge carrier separation and transfer process. [Display omitted] • Simple approaches were used to develop nanocavity assisted oxygen deficient blue TiO 2 (B) nanorods (BT) and ZnIn 2 S 4 nanosheets. • Exfoliating bulk ZnIn2S4 nanosheets into a few layers (ZIS) and integrating them on BT generates a BT/ZIS composite. • The integration of BT on ZIS accelerates charge separation and migration due to high absorption capacity and well-matched band potentials. • The optimized BT/ZIS has a high CO 2 conversion rate into CO and CH 4 , as well as great selectivity and durability. Developing new and highly stable efficient photocatalysts is crucial for achieving high performance and selective photocatalytic CO 2 conversion. In this paper, we designed a one-dimensional oxygen-deficient blue TiO 2 (B) (BT) catalyst for improved electron mobility and visible light accessibility. In addition, hexagonal ZnIn 2 S 4 (ZIS) nanosheets with a low bandgap and great visible light accessibility are employed to produce effective heterostructures with BT. The synthesized materials are tested for photocatalytic conversion of CO 2 into solar fuels (H 2 , CO and CH 4). The optimized composite yields 71.6 and 10.3 μmol g−1h−1 of CO and CH 4 , three and ten times greater than ZIS, respectively. When ZIS nanosheets are combined with a one-dimensional oxygen-deficient BT catalyst, improved electron mobility and visible light accessibility are achieved, charge carriers are effectively segregated, and the transfer process is accelerated, resulting in efficient CO 2 reduction. The photocatalytic CO 2 conversion activity of the constructed BT/ZIS heterostructures is very stable over a 10-day (240-hour) period, and CO and CH 4 production rates increase linearly with time; however, as time goes on, the rates of H 2 production decrease. Further, a five-time recycling test confirmed this, revealing essentially equal activity and selectivity throughout the experiment. As a result, CO 2 to CO and CH 4 conversion has high selectivity and longer durability. The band structure of the BT/ZIS composite is determined using Mott-Schottky measurement, diffuse reflectance spectroscopy, and valence band X-ray photoelectron spectroscopy. This research demonstrates a novel approach to investigating effective, stable, and selective photocatalytic CO 2 reduction systems for solar-to-chemical energy conversion. [ABSTRACT FROM AUTHOR]