A hybrid niobium-based oxide with bio-based porous carbon as an efficient electrocatalyst in photovoltaics: a general strategy for understanding the catalytic mechanism

Developing a high-performance catalyst and establishing a catalytic mechanism for understanding the catalytic activity are crucial to new generation photovoltaic technology. In this work, we present a feasible and general route to synthesize a bio-based porous carbon (BPC) supported ZnNb2O6 hybrid catalyst with a unique network structure, providing an effective means for electron transport between the electrode and the external circuit. Benefitting from the synergistic effect of ZnNb2O6 and BPC, a photovoltaic device assembled with the nanohybrid yields a power conversion efficiency of 8.83%, which is superior to that of pristine ZnNb2O6-based and conventional Pt-based cells (7.15% and 7.14%). Systematic electrochemical evaluations of the hybrid catalysts exhibit promising stability for practical application in photovoltaics. Contraposing the two vital functions of the counter electrode catalyst, collecting electrons and catalyzing I-3(-) reduction, we propose a general strategy to understand the potential catalytic mechanism from the band structure and surface adsorption by using first-principles density functional theory (DFT) calculations. The theoretical investigations clearly indicate that the splendid catalytic performance originates from the zero band-gap of surface metal atoms and the surface chemical adsorption interaction between I-3(-) and exposed metal atoms. The proposed general strategy in this work for synthesizing a hybrid material with a unique network structure and understanding the catalytic mechanism of the electrocatalyst can guide the design of expected catalytic nanohybrids applied in various energy fields.


Published in:
Journal Of Materials Chemistry A, 7, 24, 14864-14875
Year:
Jun 28 2019
Publisher:
Cambridge, ROYAL SOC CHEMISTRY
ISSN:
2050-7488
2050-7496
Keywords:
Laboratories:




 Record created 2019-07-24, last modified 2019-08-30


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