Tuning the Crystal Facets of MoP2 in a Phosphide-Nitride Heterostructure via Interface Engineering for Energy Efficient Ethanol Oxidation Coupled H2 Production

Abstract

Avenues to enhance the electrocatalytic activities of transition metal based nanocatalyst systems are important to improve their viability and commercial exploitation. In this work, the crystal facets of MoP2 are tailored using a controlled hydrothermal procedure to promote the electrocatalytic activity of MoP2/MoN heterojunction. The resulting heterostructure with highlighted active facets possessing similar lattice spacing from each phases display effective ethanol oxidation reaction (EOR) promoted H2 production ability in alkaline conditions. The jEOR and jHER value of 100 mA/cm2 is realized at 1.34 and -0.18 V respectively in 1.0 M KOH + 1.0 M EtOH solution supporting the activity. Furthermore, overall energy efficient H2 production is realized at relatively high j value corresponding to voltage value of 1.62 V in two-electrode arrangement. The study also revealed that, the energy efficiency is further tailorable by increasing the base strength and temperature of electrolyte. The post electrolysis characterization revealed retention of major structural features supporting the durability of the heterostructure and viability of further practical implications. The study revealed that tuning the crystal facets offers an effective mean to fine-tune the electrocatalytic behaviour and improve the energy efficiency of the overall electrocatalytic operation.