An economically sustainable bifunctional Ni@C catalyst in a solar-to-hydrogen device employing a CIGS submodule. Issue 42 (14th September 2021)

• Record Type: Journal Article
• Authors: Ngo, Quang-Tung; Omelianovych, Oleksii; Nguyen, Van-Toan; Ahn, Byung Tae; Lee, Kyu-Bock; Lee, Gyoung-Ja; Larina, Liudmila L.; Choi, Ho-Suk
• Is Part Of: Journal of materials chemistry. Volume 9:Issue 42(2021)
• Page Start: 23828
• Page End: 23840
• Publication Date: 2021-09-14
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d1ta03474j
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : In this work, Ni@C was successfully fabricated using a one-step metal wire explosion method and employed as a bifunctional catalyst material for electrodes in an electrolyzer connected to a CIGS-sub module for continuous hydrogen production. Abstract : Low-cost Ni@C core–shell nanoparticles (NPs) were synthesized by means of the electrical explosion of wire method and were applied as a bifunctional catalyst for overall water splitting. XPS, HRTEM, and BET results revealed that the carbon shell effectively protects the metallic core from oxidation while providing a porous structure that yields a high surface area, which in turn enhances the catalytic activity. Through material analysis, we established a link between synthesis conditions and resulting morphology, electronic and crystal structure of the outer layers of Ni@C NPs. Thanks to the optimum morphology and favorable shell electronic structure, Ni@C(15%) showed superior catalytic activity. An electrolyzer based on bifunctional Ni@C(15%) required only 1.71 V of voltage to deliver 10 mA cm −2 . The overpotential for water splitting is 0.12 V lower than that for a Ni benchmark electrolyzer. A stable and scalable PV-electrolysis system for water splitting that is fully based on all-inorganic CIGS PV and Ni@C(15%) was constructed. Water splitting is driven at a high current of ∼10 mA under the illumination of 100 mW cm −2, corresponding to a solar-to-hydrogen (STH) efficiency of 8.14% with 11.65% efficiency of the sub-module at the operating point. The efficiency of the STH device can be increased up to 10% by increasing the operating current through a further decrease of the Ni@C(15%) catalyst overpotential by optimization of its electronic structure.