Nitrogen-rich carbon nitride (C3N5) coupled with oxygen vacancy TiO2 arrays for efficient photocatalytic H2O2 production

Wei Gan; Xucheng Fu; Juncheng Jin; Jun Guo; Miao Zhang; Ruixin Chen; Chunsheng Ding; Yuqing Lu; Jianrou Li; Zhaoqi Sun

doi:10.1016/j.jcis.2023.09.136

Nitrogen-rich carbon nitride (C₃N₅) coupled with oxygen vacancy TiO₂ arrays for efficient photocatalytic H₂O₂ production

J Colloid Interface Sci. 2024 Jan;653(Pt B):1028-1039. doi: 10.1016/j.jcis.2023.09.136. Epub 2023 Sep 25.

Authors

Wei Gan¹, Xucheng Fu², Juncheng Jin², Jun Guo¹, Miao Zhang³, Ruixin Chen¹, Chunsheng Ding¹, Yuqing Lu¹, Jianrou Li¹, Zhaoqi Sun⁴

Affiliations

¹ School of Materials Science and Engineering, Anhui University, Hefei 230601, Anhui Province, PR China.
² College of Materials and Chemical Engineering, West Anhui University, LuAn 237015, Anhui Province, PR China.
³ School of Materials Science and Engineering, Anhui University, Hefei 230601, Anhui Province, PR China. Electronic address: zhmiao@ahu.edu.cn.
⁴ School of Materials Science and Engineering, Anhui University, Hefei 230601, Anhui Province, PR China. Electronic address: szq@ahu.edu.cn.

PMID: 37778152
DOI: 10.1016/j.jcis.2023.09.136

Abstract

Developing efficient and facilitated recycling photocatalysts for H₂O₂ formation is an ideal strategy for solar-to-chemical energy conversion. In this work, we synthesized ultrathin C₃N₅ nanosheets through the process of thermal polymerization and polyvinylpyrrolidone (PVP)-assisted solvent exfoliation. Subsequently, the obtained ultrathin C₃N₅ nanosheets were tightly attached to the surface of TiO_2-x arrays, resulting in an enhanced photocatalytic H₂O₂ production rate. The density functional theory (DFT) calculations demonstrate that an internal electric field (IEF) is generated between the TiO_2-x array and the ultrathin C₃N₅ due to the different work functions. The presence of IEF provides an additional driving force for carrier separation and transfer in the heterointerface. Benefitting from this unique strategy, the optimal heterojunction obtains the highest H₂O₂ formation rate (2.93 μmol/L/min), which is about 4.1 times than that of TiO_2-x arrays. The rotating disk electrode (RDE) analysis manifests H₂O₂ formation through 2e^--dominated oxygen reduction reaction (ORR). This research provides an innovative strategy for assembling a type-II heterojunction with a useful IEF for efficient photocatalytic H₂O₂ production.

Keywords: C(3)N(5) nanosheets; H(2)O(2) production; Oxygen vacancy TiO(2); Photocatalytic mechanism.