Vertical graphene nanowalls supported hybrid W2C/WOx composite material as an efficient non-noble metal electrocatalyst for hydrogen evolution
Shahadev Rodriguez-Miguel,
Yang Ma,
Ghulam Farid,
Roger Amade,
Rogelio Ospina,
Jose Luis Andujar,
Enric Bertran-Serra,
Stefanos Chaitoglou
Affiliations
Shahadev Rodriguez-Miguel
Department of Applied Physics, University of Barcelona, C/Martí i Franquès, 1, 08028, Barcelona, Catalunya, Spain
Yang Ma
Department of Applied Physics, University of Barcelona, C/Martí i Franquès, 1, 08028, Barcelona, Catalunya, Spain; ENPHOCAMAT Group, Institute of Nanoscience and Nanotechnology (IN2UB), University of Barcelona, C/Martí i Franquès, 1, 08028, Barcelona, Catalunya, Spain
Ghulam Farid
Department of Applied Physics, University of Barcelona, C/Martí i Franquès, 1, 08028, Barcelona, Catalunya, Spain; ENPHOCAMAT Group, Institute of Nanoscience and Nanotechnology (IN2UB), University of Barcelona, C/Martí i Franquès, 1, 08028, Barcelona, Catalunya, Spain
Roger Amade
Department of Applied Physics, University of Barcelona, C/Martí i Franquès, 1, 08028, Barcelona, Catalunya, Spain; ENPHOCAMAT Group, Institute of Nanoscience and Nanotechnology (IN2UB), University of Barcelona, C/Martí i Franquès, 1, 08028, Barcelona, Catalunya, Spain
Rogelio Ospina
Department of Applied Physics, University of Barcelona, C/Martí i Franquès, 1, 08028, Barcelona, Catalunya, Spain; ENPHOCAMAT Group, Institute of Nanoscience and Nanotechnology (IN2UB), University of Barcelona, C/Martí i Franquès, 1, 08028, Barcelona, Catalunya, Spain; Escuela de Física, Universidad Industrial de Santander, Carrera 27 calle 9 Ciudad Universitaria Bucaramanga, Colombia
Jose Luis Andujar
Department of Applied Physics, University of Barcelona, C/Martí i Franquès, 1, 08028, Barcelona, Catalunya, Spain; ENPHOCAMAT Group, Institute of Nanoscience and Nanotechnology (IN2UB), University of Barcelona, C/Martí i Franquès, 1, 08028, Barcelona, Catalunya, Spain
Enric Bertran-Serra
Department of Applied Physics, University of Barcelona, C/Martí i Franquès, 1, 08028, Barcelona, Catalunya, Spain; ENPHOCAMAT Group, Institute of Nanoscience and Nanotechnology (IN2UB), University of Barcelona, C/Martí i Franquès, 1, 08028, Barcelona, Catalunya, Spain
Stefanos Chaitoglou
Department of Applied Physics, University of Barcelona, C/Martí i Franquès, 1, 08028, Barcelona, Catalunya, Spain; ENPHOCAMAT Group, Institute of Nanoscience and Nanotechnology (IN2UB), University of Barcelona, C/Martí i Franquès, 1, 08028, Barcelona, Catalunya, Spain; Corresponding author. Department of Applied Physics, University of Barcelona, C/Martí i Franquès, 1, 08028, Barcelona, Catalunya, Spain.
Research for the development of noble metal-free electrodes for hydrogen evolution has blossomed in recent years. Transition metal carbides compounds, such as W2C, have been considered as a promising alternative to replace Pt-family metals as electrocatalysts towards hydrogen evolution reaction (HER). Moreover, hybridization of TMCs with graphene nanostructures has emerged as a reliable strategy for the preparation of compounds with high surface to volume ratio and abundant active sites. The present study focuses in the preparation of tungsten carbide/oxide compounds deposited in a three-dimensional vertical graphene nanowalls (VGNW) substrate via chemical vapor deposition, magnetron sputtering and thermal annealing processes. Structural and chemical characterization reveals the partial carburization and oxidation of the W film sputtered on the VGNWs, due to C and O migration from VGNWs towards W during the high temperature annealing process. Electrochemical characterization shows the enhanced performance of the nanostructured hybrid W2C/WOx on VGNW compound towards HER, when compared with planar W2C/WOx films. The W2C/WOx nanoparticles on VGNWs require an overpotential of −252 mV for the generation of 10 mA cm−2. Chronoamperometry tests in high overpotentials reveal the compounds stability while sustaining high currents, in the order of hundreds of mA. Post-chronoamperometry test XPS characterization unveils the formation of a W hydroxide layer which favours hydrogen evolution in acidic electrolytes. We aspire that the presented insights can be valuable for those working on the preparation of hybrid electrodes for electrochemical processes.
