6533b7d3fe1ef96bd1261544

RESEARCH PRODUCT

Solution-Processed Ni-Based Nanocomposite Electrocatalysts: An Approach to Highly Efficient Electrochemical Water Splitting

subject

description

In this study, we report an up-scalable and low-cost solution-processed method to in situ synthesize an earth-abundant non-stoichiometric NiOx-based electrocatalytic film for water oxidation. The catalytic activity was found to be inversely proportional to the baking temperature, which varied from 50 to 500 °C. We found the formation of a hybrid nanocomposite thin film of NiOx nanocrystals (<2 nm size) inside an acetate-based organic matrix at low temperatures (<200 °C). The defective and short-range structural order of the NiOx-based nanocomposite electrocatalysts, compatible with lattice stress, low electrical conductivity, and high density of catalytically active surface species, and higher Fe incorporation were responsible for the enhanced electrocatalytic activity. Our champion NiOx catalyst features a 358 mV overpotential at 10 mA cm–2 and more than 60 h of continuous operation without significant losses, which is a remarkable milestone for undoped NiOx electrocatalysts synthesized at nearly room temperature by a solution-processed up-scalable method. Funding for open access charge: CRUE-Universitat Jaume I The authors acknowledge the financial support from the Ministerio de Ciencia, Innovación y Universidades of Spain through funded projects ENE2017-85087-C3-1-R, RYC-2015-18349, and TEC2017-86102-C2-1-R and Agencia Valenciana de la Innovacion (AVI) INNVAL10/18/032. The authors thank the Central Support Service for Experimental Research (SCSIE) (XRD and SEM facilities) and the Institute of Materials Science (TGA and DTA equipment) of the University of Valencia and the Central Service of Scientific Instrumentation (SCIC) at University Jaume I. The authors also thank Prof. Juan P. Martinez-Pastor for his constructive suggestions and scientific discussions.