CoO/g-C3N4 p-n heterojunction catalyst in-situ loading CoP for enhanced photocatalytic H2 evolution

Abstract

A prospective and pollution-free approach for producing hydrogen is photocatalytic water-splitting. Designing and developing a catalyst that can separate the photogenerated carriers and offer enough H+ reduction active sites are of paramount importance in boosting the efficiency of photocatalytic H2 evolution. Herein, the cocatalyst CoP were loaded on CoO/g-C3N4 p-n heterojunction (CoP/CoO/CN, referring g-C3N4 to as CN) by an in-situ phosphating method, and its H2 evolution activity was measured by simulating sunlight irradiation without adding any noble metal cocatalyst. The CoP/CoO/CN photocatalyst exhibited a better H2 evolution activity (4036.97 μmol·g−1·h−1) than Pt/CN. The mechanism study demonstrated that the excellent activity is resulted from the formed internal electric field in p-n heterojunction, and the enough active reduction sites from cocatalyst CoP. This work provides a rational design for in-situ loading cocatalysts on heterojunction and is helpful for developing efficient photocatalysts using the abundant low-cost elements.