Synthesis of SrTiO3 submicron cubes with simultaneous and competitive photocatalytic activity for H2O splitting and CO2 reduction

Haoshan Wei; Jingyi Cai; Yong Zhang; Xueru Zhang; Elena A Baranova; Jiewu Cui; Yan Wang; Xia Shu; Yongqiang Qin; Jiaqin Liu; Yucheng Wu

doi:10.1039/d0ra08246e

Synthesis of SrTiO₃ submicron cubes with simultaneous and competitive photocatalytic activity for H₂O splitting and CO₂ reduction

RSC Adv. 2020 Nov 24;10(70):42619-42627. doi: 10.1039/d0ra08246e. eCollection 2020 Nov 23.

Authors

Haoshan Wei^{1

2}, Jingyi Cai^{1

2}, Yong Zhang^{1

2}, Xueru Zhang³, Elena A Baranova^{4

5}, Jiewu Cui^{1

2}, Yan Wang^{1

2}, Xia Shu^{1

2}, Yongqiang Qin^{1

2}, Jiaqin Liu^{2

6}, Yucheng Wu^{1

2}

Affiliations

¹ School of Materials Science and Engineering, Hefei University of Technology Hefei 230009 Anhui China zhangyong.mse@hfut.edu.cn ycwu@hfut.edu.cn.
² Key Laboratory of Advanced Functional Materials and Devices of Anhui Province Hefei 230009 Anhui China.
³ Instrumental Analysis Center, Hefei University of Technology Hefei 230009 China.
⁴ China International S&T Cooperation Base for Advanced Energy and Environmental Materials Hefei 230009 Anhui China.
⁵ Department of Chemical and Biological Engineering, Centre for Catalysis Research and Innovation (CCRI), University of Ottawa 161 Louis-Pasteur Ottawa ON K1N 6N5 Canada.
⁶ Institute of Industry & Equipment Technology, Hefei University of Technology Hefei 230009 Anhui China.

Abstract

Single crystalline strontium titanate (SrTiO₃) submicron cubes have been synthesized based on a molten salt method. The submicron cubes showed superior photocatalytic activity towards both water splitting and carbon dioxide reduction, in which methane (CH₄) and hydrogen (H₂) were simultaneously produced. The average production rate of methane up to 8 h is 4.39 μmol g^-1 h^-1 but drops to 0.46 μmol g^-1 h^-1. However, the average production rate of hydrogen is 14.52 before 8 h but then increases to 120.23 μmol g^-1 h^-1 after 8 h. The rate change of the two processes confirms the competition between the H₂O splitting and CO₂ reduction reactions. Band structure and surface characteristics of the SrTiO₃ submicron cubes were characterized by diffuse reflective UV-Vis spectroscopy, Mott-Schottky analysis, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The results reveal that the simultaneous and competitive production of methane and hydrogen is due to a thermodynamics factor, as well as the competition between the adsorption of carbon dioxide and water molecules on the surface of the faceted SrTiO₃. This work demonstrates that SrTiO₃ photocatalysts are efficient in producing sustainable fuels via water splitting and carbon dioxide reduction reactions.