1 Shaanxi Key Laboratory for Advanced Energy Devices, Key Laboratory for Macromolecular Science of Shaanxi Province, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, Shaanxi, P. R. China. jiaxing@snnu.edu.cn.
2 College of Chemistry and Materials, Weinan Normal University, Weinan 714099, P. R. China.
3 Key Laboratory for Green Chemical Process of Ministry of Education, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430073, P. R. China.
4 School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China.
Expression of concern for 'Enhanced photocatalytic activity of g-C3N4/MnO composites for hydrogen evolution under visible light' by Na Mao et al., Dalton Trans., 2019, 48, 14864-14872, https://doi.org/10.1039/C9DT02748C.