Precisely modifying Co2P/black TiO2 S-scheme heterojunction by in situ formed P and C dopants for enhanced photocatalytic H2 production.

The construction of S-scheme heterojunction catalysts is promising for efficient photocatalytic hydrogen production, but the conscious modulation of S-scheme charge transfer has remained largely underdeveloped. Herein, P and C modified Co 2 P/black TiO 2 S-scheme heterojunction photocatalyst (Co 2 P/PC- b -TiO 2) is prepared by pyrolyzing a mixture of cobalt phosphonate and TiO 2 under H 2 atmosphere. The in situ formed P and C dopants can not only enhance the ratio of surface active O species to bulk O defects but also inhibit anatase-to-rutile phase transformation, thereby ensuring the high intrinsic activity. More importantly, the S-scheme heterojunction between PC- b -TiO 2 and Co 2 P is modified by the incorporation of P and C, wherein the intimately coupled heterointerface and strong internal electric field can accelerate charge separation and migration and optimize the available redox potential. Accordingly, Co 2 P/PC- b -TiO 2 displays dramatically ascendant photocatalytic hydrogen evolution performance and outstanding stability. This study provides guidance for elaborately modifying S-scheme heterojunctions through heteroatom doping and heralds a new paradigm for engineering advanced heterojunction catalysts. [Display omitted] • S-scheme heterojunction modification strategy is performed on P,C-dual-doped Co 2 P/black TiO 2. • P and C dopants create high intrinsic activity, intimate heterointerface and strong internal electric field. • Modified S-scheme heterojunction accelerates charge separation and migration and optimizes available redox potential. • Co 2 P/PC- b -TiO 2 displays dramatically ascendant photocatalytic hydrogen evolution performance. [ABSTRACT FROM AUTHOR]