Boosting catalytic performance of hierarchical Co/Co0.85Se microspheres via Mott-Schottky effect toward triiodide reduction and alkaline hydrogen evolution

• Published in: Journal of alloys and compounds Vol. 918; p. 165608
• Main Authors: Song, Tianshu, Zhang, Zhuanfan, Zhao, Bing, Wang, Liyan, Kan, Wei, Sun, Li, Wang, Xiuwen
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.10.2022; Elsevier BV
• Subjects: Bifunctional catalysts; Catalysts; Catalytic activity; Chemical reduction; Control equipment; Dye-sensitized solar cell; Dye-sensitized solar cells; Energy conversion; Heterojunctions; Heterostructure; Hierarchical structure; Hydrogen evolution reaction; Hydrogen evolution reactions; Microspheres; Photoelectricity; Selenides; Structural hierarchy; Synergistic effect; Transition metals; Bifunctional catalysts; Heterostructure; Dye-sensitized solar cell; Hydrogen evolution reaction; Hierarchical structure
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.165608

Interface engineered composites composing of metal and transition metal selenides have been deemed as promising substitutes as noble Pt in the fields of the energy conversion. Herein, the well-defined hierarchical Co/Co0.85Se microsphere with Mott-Schottky (M-S) effect was synthesized by the facile solvothermal method (Co/Co0.85Se-3). Interestingly, the as-obtained 3D Co0.85Se microsphere was assembled by 2D porous nanosheets. The characteristics including M-S heterojunction and hierarchical structure endows Co/Co0.85Se microsphere with high specific surface area, good conductivity, and synergistic effect between metal Co and Co0.85Se. More concretely, the optimized Co/Co0.85Se exhibits outstanding catalytic activity toward triiodide reduction reaction (IRR). When employed as the counter electrode (CE) catalyst for dye-sensitized solar cell (DSSC), a photoelectric conversion efficiency (PCE) of 8.31 % is achieved, which is 3.36 % higher than that of Pt-control device (8.04 %). Moreover, Co/Co0.85Se-3 displays remarkable catalytic activity for hydrogen evolution reaction (HER) with a low overpotential of 107 mV at the current density of 10 mA cm−2 under alkaline condition (1.0 M KOH), accompanying with Tafel slope of 140 mV dec−1. Our discovery provides an effective approach to develop the cost-effective advanced catalysts to promote the application of DSSC and HER. The hierarchical Co/Co0.85Se microspheres with unique Mott-Schottky structure exhibited excellent catalytic performance in the fields of DSSC and HER. [Display omitted] •Hierarchical Co/Co0.85Se microsphere with M-S effect was synthesized.•Synergy between Co and Co0.85Se increases the catalytic activity of Co/Co0.85Se-3.•Performance of Co/Co0.85Se-3 for DSSC was higher than that of Pt.•Co/Co0.85Se-3 exhibited remarkable catalytic property for alkaline HERs.