Micro-regulating defect-charge delocalization in Cr-doped SrTiO3 for boosting visible-light-driven overall water splitting

Difficulties in developing efficient visible-light-response photocatalysts have led to a lack of optimism in the utilization of large-scale solar energy. This article enhances the understanding of the Cr-SrTiO3 3 catalyst for photocatalytic overall water splitting from the perspective of micro-regulation of Ti3+ 3+ defects and oxygen vacancy concentration. The advanced characterization techniques including XPS and EPR confirm these analyses. Compared to pure Cr-SrTiO3, 3 , the Na, Cr-SrTiO3 3 achieve a H2 2 production of 40.09 mu mol center dot h-1,- 1 , indicating that adjusting the defect state can have a major impact on carrier migration. In addition, DFT calculations show that the phenomenon of charge localization varies with the introduction of Na+/K+/Cs+, + /K + /Cs + , and compared to pure SrTiO3 3 and Cr-SrTiO3, 3 , the additional introduction of Na+ + causes the best delocalization properties cooperating with Cr3+, 3+ , indicating a significant transition from deep traps centered on Ti3+ 3+ to shallow defects, which is the key to improving photocatalytic activity.