Rh2S3/N‐Doped Carbon Hybrids as pH‐Universal Bifunctional Electrocatalysts for Energy‐Saving Hydrogen Evolution. Issue 9 (25th May 2020) - Zhang, Chaoxiong
Abstract: Using hydrazine oxidation reaction (HzOR) to replace the oxygen evolution reaction is an effective way to decrease the overpotential of the anodic reaction in overall water splitting (OWS), facilitating cost‐effective and safe hydrogen production. Herein, Rh2 S3 /N‐doped carbon hybrids (Rh2 S3 /NC) are first reported as novel and efficient bifunctional electrocatalysts for hydrazine‐assisted hydrogen generation over a wide pH range. Specifically, Rh2 S3 /NC exhibits low overpotentials for the hydrogen evolution reaction (HER) in alkaline (38 mV), neutral (46 mV), and acidic (21 mV) electrolytes, to reach the current density of 10 mA cm −2, and maintains the activities over 70 h. Meanwhile, Rh2 S3 /NC also displays competitive HzOR performance at all‐pH electrolytes. Thus, serving as a bifunctional electrocatalyst for both HER and HzOR, Rh2 S3 /NC shows overwhelming‐Pt/C performance in three electrolytes, and can save over 93.3%, 85.2%, and 78.3% energy consumption compared to the corresponding OWS system. Moreover, theoretical calculations confirm that Rh2 S3 /NC owns low free‐energy changes of the H adsorption and the dehydrogenation of adsorbed NHNH both of which are beneficial to enhance catalytic activity. This work develops a novel bifunctional electrocatalyst with free pH‐dependent condition for the hydrazine‐assisted electrolysis system to furtherly reduce the cost of massive industrial H2 production. Abstract : Rh2 S3 nanoparticles anchored on N‐doped carbon can be functioned as a high‐efficiency and durable catalyst for electrocatalytic hydrogen evolution and hydrazine oxidation reactions over a wide pH range with ultralow overpotentials. When used in overall hydrazine splitting as a bifunctional electrocatalyst, it exhibits surpassing‐Pt/C performance in basic and acidic solutions.