Driving sustainability: integrating hydrogen production and wastewater treatment via advanced noble metals-free electrodes

Currently, the transition toward clean energy systems that do not emit carbon dioxide is an urgent task for the creation of a sustainable energy society, in line with Goal 7 of the 2030 Agenda [1]. In this context, hydrogen (H2) emerges as a promising energy storage medium. Unfortunately, approximately 96% of its production relies on non-renewable sources, while only 4% originates from water splitting. In this latter, a considerable electrochemical overpotential is needed to trigger the hydrogen evolution reaction (HER) on the electrode surface. Moreover, highly efficient working electrode requires the use of electrocatalysts to minimize the energy barrier associated with HER. For these reasons, this method is costly [2]. In the last decades, it has been demonstrated that organic pollutants in wastewaters containing high level of chemical energy are excellent electron donor and suitable candidates for H2 production [3]. This promising approach could also help in solving the issues related to the environmental pollution. Based on these premises, this research focuses on the use of a noble metal-free cathode, for efficient hydrogen generation from simulated wastewater through water splitting, with this innovative approach, the double goal of clean energy system and wastewater treatment can be matched.