Development of Electronically Tuned Nanomaterials for Electrocatalysis

Abstract

A green energy-dependent sustainable future can be promised by converting and storing renewable energies in terms of chemical fuels like hydrogen through electrochemical water splitting. However, the requirements of high overpotential to overcome the energy barriers of both hydrogen and oxygen evolution reactions (HER and OER) restrict the overall efficiency of hydrogen generation by electrocatalysis of water. Noble metal based electrocatalysts (platinum, iridium, ruthenium) have been believed as ideal electrocatalysts due to their high activity, selectivity and optimal adsorption ability for HER, OER reaction intermediates. However, their high cost and scarcity compelled scientists to search for new, cost-effective and simple strategies for the development of efficient electrocatalysts. In this regard, rational design of heterostructures and anchoring single-atom catalysts (SAC) on adequate support are the two successful strategies to lower the overpotentials for HER and OER processes. Though substantial work has been presented in the literature based on efficient heterostructure and SAC development, the used conventional methods are extremely time-consuming, energy inefficient and complex. In addition, high quality atomistic interfacing in heterostructure development is difficult to realize due to the multi-step process requirement of the conventional strategies. Stabilization of SACs over a proper support is also very challenging yet important to synergistically enhance catalytic activity of the system specially in the dynamic OER environment where usually reconstruction of the catalyst happens. These challenges drastically reduce the efficiency of the catalysts and increase the required overpotential for HER and OER