Mott-Schottky heterostructure significantly decreases energy required for water splitting
Mott-Schottky heterostructure significantly decreases energy required for water splitting lead image
Rapid electron transfer and mass transport during the high current density hydrogen evolution reaction remain key parts of optimizing water electrolysis — splitting water into its oxygen and hydrogen components. One type of material investigated for industrial-level hydrogen production, Mott-Schottky catalysts, are heterostructures that offer mass transport, regulate density states, and create a synergistic effect at the metal–semiconductor interface.
Researchers have developed a Mott-Schottky heterostructure that greatly reduces the energy demands of water splitting. Through density functional theory (DFT) simulations, experimental hydrothermal synthesis and controlled urea pyrolysis, Hao et al. have produced a electrode made of nickel, molybdenum and nitrogen, Ni/NiMoN, that promotes hydrogen spillover effects while optimizing hydrogen adsorption/desorption energetics.
The work highlights the central importance of superwettability, the ability to strongly segregate hydrophobic and hydrophilic phases, in developing large-scale electrolysis systems.
“This study specifically targets the persistent issues of overpotential and catalyst instability during high current density hydrogen evolution reaction,” said author Bo Wei. “By engineering Ni/NiMoN heterostructures with tailored superwettability, we presented comprehensive experimental and theoretical analysis of electron transfer and hydrogen spillover for scalable and efficient green hydrogen generation.”
The Ni/NiMoN electrode minimized bubble adhesion through its simultaneous avoidance of air and attraction to water, driving its enhanced mass transport efficiency.
DFT studies on the catalyst pointed to the nickel nanoparticles as substantially promoting hydrogen spillover effects while optimizing hydrogen adsorption/desorption energetics, achieving an ultralow overpotential of 231.3 millivolts at 1000 milliamperes per square centimeter. Simulations showed this performance could be sustained over 1000 hours, a landmark for such devices.
The group looks to continue developing advanced heterostructures by leveraging machine learning, prototyping catalysts in larger-scale work, and examining chloride corrosion, an obstacle to seawater electrolysis.
Source: “Hydrogen spillover in superwetting Ni/NiMoN Mott-Schottky heterostructures for boosting ampere-level hydrogen evolution,” by Hongru Hao, Yu Zhang, Zhe Wang, Shuo Shen, Lingling Xu, Zhe Lv, Yanqing Shen, and Bo Wei, Applied Physics Letters (2025). The article can be accessed at https://doi.org/10.1063/5.0250821 .
