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

• Published in: Applied surface science 2023-12, Vol.639, p.158180, Article 158180
• Main Authors: Li, Yang, Li, Yue, Yang, Cai, Yu, Chang-Ping, Gan, Li-Hua
• Format: Article
• Language: English
• Subjects: g-C3N4; In-situ phosphating; Internal electric field; p-n heterojunction; Photocatalytic water-splitting
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2023.158180

[Display omitted] •The novel CoP/CoO/g-C3N4 photocatalyst was successfully developed by loading the co-catalyst CoP onto CoO/g-C3N4 p-n heterojunction by in-situ phosphating.•A highly active CoP/CoO/g-C3N4 photocatalyst was developed using abundant low-cost elements, and the optimized CoP/CoO/g-C3N4 photocatalyst exhibited a better H2 evolution activity (4036.97 μmol·g−1·h−1) than Pt/g-C3N4.•The charge transfer and intermediate H* adsorption energy were calculated by DFT studies, and the hydrogen evolution mechanism of this photocatalyst was proposed. 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.