Ni-decorated WS <sub>2</sub> -WSe <sub>2</sub> heterostructure as a novel sensing candidate upon C <sub>2</sub> H <sub>2</sub> and C <sub>2</sub> H <sub>4</sub> in oil-filled transformers: a first-principles investigation
Hai‐Long Wu, Shan Zhong, Yuejing Bin, Xiaoping Jiang, Hao Cui
Abstract
Using the first-principles theory, this work delves into the gas adsorption and sensing properties of Ni-decorated WS2-WSe2 (Ni@WS2-WSe2) heterojunction upon C2H2 and C2H4, in order to perform the dissolved gas analysis and evaluate the operation status of the oil-filled transformers. We perform the adsorption of a single Ni atom onto the WS2-WSe2 heterojunction to establish the purposed material and find its good stability with the formation energy of −2.94 eV. The chemisorption is identified for the gas-surface interaction with the adsorption energies of −1.54 eV for C2H2 and −1.58 eV for C2H4, respectively. The electronic property deformation of the Ni@WS2-WSe2 is illustrated and the gas sensing responses upon two gas species are theoretical calculated based on the change of bandgap. Moreover, the recovery property is analyzed as well to verify the reusability of Ni@WS2-WSe2, with favorable C2H2 and C2H4 desorption time of 0.38 and 0.96 s at 498 K, respectively. These findings highlight the potential of Ni@WS2-WSe2 as a reusable and highly sensitive gas sensor for dissolved gas analysis in oil-filled transformers, thus paving the way for further intriguing investigations on heterostructure-based sensing material for applications in various industrial and environmental settings.