Researchers at the Institute of Nano Science and Technology (INST) in Mohali have made significant advancements in the field of green hydrogen generation. By focusing on proton adsorption behavior at the surface of catalysts, they have developed insights that can pave the way for constructing electrocatalysts beneficial for producing green hydrogen. The study delves into the utilization of metal-oxide-semiconductor (MOS) based p-n heterojunctions, particularly the CuO-CuWO4 catalyst, which exhibits robust built-in electric fields (BIEF) due to its asymmetric electronic environment. Through detailed analysis of parameters like work function, Gibbs free energy, and BIEF, researchers have uncovered the mechanism behind enhanced hydrogen production. The research demonstrates that the CuO-CuWO4 catalyst not only optimizes hydrogen bonding but also displays negative cooperativity, enhancing the efficiency of hydrogen evolution. By leveraging the interplay between BIEF and Gibbs free energy, the catalyst promotes alkaline Hydrogen Evolution Reaction by improving proton adsorption and desorption dynamics. This breakthrough in electrocatalytic hydrogen production, as published in Adv. Energy Mater. 2025, opens doors for designing similar efficient electrocatalysts, thereby contributing towards a sustainable environment with advanced green technologies.