Metal-organic framework-derived Ni–Co alloy@carbon microspheres as high-performance counter electrode catalysts for dye-sensitized solar cells

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2018-02, Vol.334, p.419-431
• Main Authors: Jiang, Xiancai, Li, Hongmei, Li, Shuolin, Huang, Shaowei, Zhu, Changli, Hou, Linxi
• Format: Article
• Language: English
• Subjects: Counter electrode; Dye-sensitized solar cells; Electrochemical performance; Metal-organic frameworks; Ni–Co alloy@carbon microspheres
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2017.10.043

[Display omitted] •Ni–Co alloy@C microspheres were synthesized by a simple self-sacrificing template method.•Their structures and electrochemical performance can be adjusted by altering the Co/Ni molar ratio.•Ni–Co alloy@C CEs showed excellent electrocatalytic activity and conductivity.•The NiCo0.2@C hollow microspheres yielded a higher PCE (9.30%) than Pt CE (8.04%). Spherical-structured nano-/micromaterials with tunable shell architectures and compositions are becoming increasingly important and attractive for electrochemical energy conversion and storage. Herein, we report the synthesis of novel Ni–Co alloy@carbon microspheres by calcining Co/Ni bimetallic metal-organic frameworks (MOFs) prepared by a facile solvothermal reaction. Their structures, dimensions and electrochemical performance can be optimized by simply tuning the Co/Ni molar ratio. Benefiting from the advantageous structural and compositional features, the obtained Ni–Co alloy@carbon microspheres display exceptional electrochemical performance when used as counter electrode (CE) catalysts for dye-sensitized solar cells (DSSCs). In particular, the optimized NiCo0.2@C CE delivers an impressive power conversion efficiency (PCE) of 9.30%, showing a ∼15.7% enhancement compared to that of Pt CE (8.04%). Additionally, the NiCo0.2@C CE also demonstrates a good long-term electrochemical stability for the I3−/I− electrolyte. This work may provide new options for the design and preparation of efficient electrocatalysts with novel morphologies and desirable compositions.