Promoting CdS photocatalytic activity through a coating layer of solid electrolyte LiTi2(PO4)3

Abstract

Two major challenges in photocatalysis are the separation and utilization of photogenerated charge carriers that have limited their wider applications. To address these issues, significant studies have been devoted to the surface modification of photocatalysts. Herein, CdS nanorods were surface-modified by an ion-conducting LiTi2(PO4)3 (LTP) shell. This modification could accelerate the rapid separation and efficient utilization of photoinduced charge carriers. Therefore, CdS@LTP composite photocatalyst displayed a photocatalytic H2 evolution rate of 26.01 mmol g−1h−1 without any addition of cocatalysts in a Na2S/Na2SO3 solution, which was over 6-fold compared to CdS, and showed improved stability. Furthermore, this shell can prevent the reverse reactions between H2 and O2 during photocatalytic water splitting. With the photo-deposition of Pt cocatalysts, CdS@LTP-Pt can achieve efficient overall water splitting with the highest H2 generation rate (351 μmol g−1h−1), which is 3.25 times higher than that of CdS-Pt. This study broadens the application of ionic conductor materials and provides a new way for the design of advanced photocatalysts for solar energy conversion.