Hollow prussian blue analog@defect-rich layered double hydroxide S-scheme heterojunctions toward optimized photothermal-photocatalytic performance

Effective photogenerated charge separation in the photocatalytic process is a crucial issue. Herein, hollow Prussian blue analog@defect-rich layered double hydroxide S-scheme heterojunctions are successfully obtained by two-sept etching strategies. Firstly, the hollow Prussian blue analog (H-PBA) is formed by ammonia etching. Subsequently, ZIF-67 is uniformly grown on the H-PBA surface and formed into defect-rich layered double hydroxide (D-LDH) nanocages by ion exchange. This hollow core-shell structure of H-PBA@D-LDH enables the photocatalyst to have more active sites. Meanwhile, in-situ XPS and the work function revealed the direction of electron transfer, providing evidence for the formation of S-scheme heterojunctions. In addition, transient photoluminescence and photoelectrochemical tests confirmed that the H-PBA@D-LDH S-scheme heterojunctions had longer charge lifetimes and enhanced photoelectrochemical properties. The presence of photothermal effect increases the temperature of the H-PBA@D-LDH composite system, which promotes the photocatalytic process. As a result, the H-PBA@D-LDH S-scheme heterojunction exhibited excellent photocatalytic degradation efficiency and hydrogen production rate (260.320 mu mol h-1), which were several times higher than those of H-PBA and D-LDH. This work provides a new idea for the design of S-scheme photocatalysts.

Automated summary

Hollow Prussian blue analog@defect-rich layered double hydroxide S-scheme heterojunctions were successfully synthesized using two-step etching strategies. The hollow core-shell structure provided more active sites, and in-situ XPS and work function analysis confirmed the formation of S-scheme heterojunctions. Transient photoluminescence and photoelectrochemical tests demonstrated longer charge lifetimes and enhanced photoelectrochemical properties. The presence of photothermal effect increased the reaction temperature and promoted the photocatalytic process. This research presents a new idea for the design of S-scheme photocatalysts.