Efficient solar fuel production enabled by an iodide oxidation reaction on atomic layer deposited MoS2

• Published in: Carbon energy 2023-12, Vol.5 (12), p.n/a
• Main Authors: Park, Young Sun, Jang, Gyumin, Sohn, Inkyu, Lee, Hyungsoo, Tan, Jeiwan, Yun, Juwon, Ma, Sunihl, Lee, Jeongyoub, Lee, Chan Uk, Moon, Subin, Im, Hayoung, Chung, Seung‐Min, Yu, Seungho, Kim, Hyungjun, Moon, Jooho
• Format: Article
• Language: English
• Subjects: Alternative energy; Atomic layer epitaxy; Catalysts; Contact angle; Current density; Durability; Electrocatalysts; Electrochemistry; Electrodes; Electrons; Fuel production; Heterostructures; Hydrogen; Hydrogen evolution reactions; Hydrogen production; iodide oxidation reaction; Iodides; Molybdenum; Molybdenum disulfide; molybdenum sulfide; Oxidation; Oxygen evolution reactions; Perovskites; Photovoltaic cells; Photovoltaics; photovoltaic–electrochemical hydrogen production; Reaction kinetics; solar hydrogen; Spectrum analysis; Substrates; Thermodynamics; Transmission electron microscopy; Water splitting
• ISSN: 2637-9368; 2637-9368
• DOI: 10.1002/cey2.366

Oxygen evolution reaction (OER) as a half‐anodic reaction of water splitting hinders the overall reaction efficiency owing to its thermodynamic and kinetic limitations. Iodide oxidation reaction (IOR) with low thermodynamic barrier and rapid reaction kinetics is a promising alternative to the OER. Herein, we present a molybdenum disulfide (MoS2) electrocatalyst for a high‐efficiency and remarkably durable anode enabling IOR. MoS2 nanosheets deposited on a porous carbon paper via atomic layer deposition show an IOR current density of 10 mA cm–2 at an anodic potential of 0.63 V with respect to the reversible hydrogen electrode owing to the porous substrate as well as the intrinsic iodide oxidation capability of MoS2 as confirmed by theoretical calculations. The lower positive potential applied to the MoS2‐based heterostructure during IOR electrocatalysis prevents deterioration of the active sites on MoS2, resulting in exceptional durability of 200 h. Subsequently, we fabricate a two‐electrode system comprising a MoS2 anode for IOR combined with a commercial Pt@C catalyst cathode for hydrogen evolution reaction. Moreover, the photovoltaic–electrochemical hydrogen production device comprising this electrolyzer and a single perovskite photovoltaic cell shows a record‐high current density of 21 mA cm–2 at 1 sun under unbiased conditions. A MoS2 catalyst is uniformly deposited on carbon paper using the atomic layer deposition process. The MoS2‐based heterostructure anode for iodide oxidation reaction (IOR) combined with a Pt@C cathode for hydrogen evolution reaction delivers 10 mA cm−2 at a low cell voltage of 0.66 V. By connecting this electrolyzer with a single perovskite photovoltaic cell, the resulting photovoltaic–electrochemical device coupled with IOR produces a record‐high current density of 21 mA cm−2 without external bias.