Jenni Lie, Felycia Edi Soetaredjo, Hardy Shuwanto, Hairus Abdullah, Suryadi Ismadji, Idaa Warmadewanthi
The worsening conditions of global warming caused by fossil fuels still remains the hottest issue to date. Hydrogen, as one of the most prospective renewable energies, was extensively developed to replace fossil energy sources. Besides, the transition to an electrification system has led to a massive use of lithium-ion batteries (LIB), which cannot be missed because of the huge amount of waste that can harm our environment. Rather than disposing of spent LIBs, this work utilized the spent LIBs, performed subcritical water treatment using different acids (HNO3, H2SO4, HCl, and ascorbic acid), and applied them in photocatalytic hydrogen evolution reaction (HER). In brief, subcritical water treatment using HCl (LIB-C) demonstrated the most optimum photocatalytic HER activities, with an evolved hydrogen amount of 28.7 μmol within 5 h of solar-light irradiation in a 10% ethanolic solution. It was found that the reduction of metal compounds (Co and Mn) to lower valences occurred in LIB-C samples, which are preferred for photocatalytic water reduction to generate hydrogen because low valences of metals are more available to be oxidized to higher valences, Co2+ to Co3+ and Mn2+ to Mn3+ or Mn4+,. © 2024 American Chemical Society.
Department of Chemical Engineering, Widya Mandala Surabaya Catholic University, Kalijudan 37, Surabaya, 60114, Indonesia; Collaborative Research Center for Zero Waste and Sustainability, National Research and Innovation Agency, Bandung, 40135, Indonesia; Taiwan−Indonesia Science and Technology Innovation Center (TI-STIC), Kalijudan 37, Surabaya, 60114, Indonesia; Department of Industrial Engineering, Universitas Prima Indonesia, Sampul 3, Medan, 20118, Indonesia; Department of Materials Science and Engineering, National Taiwan University of Science and Technology, No. 43, Section 4, Keelung Road, Taipei, 10607, Taiwan; Department of Environmental Engineering, Faculty of Civil, Planning, and Geo Engineering, Institut Teknologi Sepuluh Nopember, Kampus ITS Sukolilo, Surabaya, 60111, Indonesia