CoO and g-C3N4 complement each other for highly efficient overall water splitting under visible light

• Published in: Applied catalysis. B, Environmental Vol. 226; pp. 412 - 420
• Main Authors: Guo, Feng, Shi, Weilong, Zhu, Cheng, Li, Hao, Kang, Zhenhui
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.06.2018
• Subjects: CoO nanoparticles; g-C3N4; H2O2-resisitence poisoning; Overall water splitting; Photothermal deactivation; g-C3N4; CoO nanoparticles; Photothermal deactivation; H2O2-resisitence poisoning; Overall water splitting
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2017.12.064

CoO/g-C3N4 heterojunction photocatalysts were fabricated through a facile solvothermal method for overall water splitting. Simultaneous evolution of H2 and O2 from pure water with the stoichiometric ratio of about 2:1 achieved with all the CoO/g-C3N4 heterojunctions as catalysts under visible light irradiation. Among of them, 30 wt.% CoO/g-C3N4 with H2 evolution rate of 2.51 μmol/h and O2 evolution rate of 1.39 μmol/h also exhibited remarkably higher photocatalytic performance and stability (over 15 cycles) than single CoO or g-C3N4. This enhanced photocatalytic activity of CoO/g-C3N4 heterojunction can be ascribed to the synergistic effect of the junction and interface formed between CoO and g-C3N4. In addition, the sufficient long lifetime stability of CoO/g-C3N4 comes from the complementary advantages effect between CoO and g-C3N4, as is proved, CoO can protect g-C3N4 from H2O2 poisoning, and simultaneously the photo-induced heat from CoO during the photocatalytic process responsible for the rapid deactivation can be timely conducted to g-C3N4. [Display omitted] •CoO/g-C3N4 heterojunctions were synthesized by one-step solvothermal method.•CoO/g-C3N4 heterojunctions exhibited outstanding photocatalytic activity and stability.•Long-term stability of CoO/g-C3N4 heterojunctions comes from the complementary advantages effect between CoO and g-C3N4. Photocatalytic hydrogen production from overall water splitting is a clean and renewable technology that can convert solar energy into chemical energy, for which developing an efficient and stable photocatalyst has been the central scientific topic. Herein, CoO/g-C3N4 heterojunction photocatalysts were fabricated through a facile solvothermal method for overall water splitting. Simultaneous evolution of H2 and O2 from pure water with the stoichiometric ratio of about 2:1 achieved with all the CoO/g-C3N4 heterojunctions as catalysts under visible light irradiation. Among of them, 30 wt.% CoO/g-C3N4 with H2 evolution rate of 2.51 μmol/h and O2 evolution rate of 1.39 μmol/h also exhibited remarkably higher photocatalytic performance and stability (over 15 cycles) than single CoO or g-C3N4. This enhanced photocatalytic activity of CoO/g-C3N4 heterojunction can be ascribed to the synergistic effect of junction and interface formed between CoO and g-C3N4. In addition, the sufficient long lifetime stability of CoO/g-C3N4 comes from the complementary advantages effect between CoO and g-C3N4, as is proved, CoO can protect g-C3N4 from H2O2 poisoning, and simultaneously the photo-induced heat from CoO during the photocatalytic process responsible for the rapid deactivation can be timely conducted to g-C3N4.