Covalently Bonded Ir(IV) on Conducted Blue TiO2 for Efficient Electrocatalytic Oxygen Evolution Reaction in Acid Media

Chau T K Nguyen,Ngoc Quang Tran,Hyoyoung Lee,Thi Anh Le

doi:10.3390/catal11101176

Chau T K Nguyen, Ngoc Quang Tran + Show 2 more

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https://doi.org/10.3390/catal11101176

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Abstract

The stability of anode electrode has been a primary obstacle for the oxygen evolution reaction (OER) in acid media. We design Ir-oxygen of hydroxyl-rich blue TiO2 through covalent bonds (Ir–O2–2Ti) and investigate the outcome of favored exposure of different amounts of covalent Ir–oxygen linked to the conductive blue TiO2 in the acidic OER. The Ir-oxygen-blue TiO2 nanoclusters show a strong synergy in terms of improved conductivity and tiny amount usage of Ir by using blue TiO2 supporter, and enhanced stability using covalent Ir-oxygen-linking (i.e., Ir oxide) in acid media, leading to high acidic OER performance with a current density of 10 mA cm−2 at an overpotential of 342 mV, which is much higher than that of IrO2 at 438 mV in 0.1 M HClO4 electrolyte. Notably, the Ir–O2–2Ti has a great mass activity of 1.38 A/mgIr at an overpotential 350 mV, which is almost 27 times higher than the mass activity of IrO2 at the same overpotential. Therefore, our work provides some insight into non-costly, highly enhanced, and stable electrocatalysts for the OER in acid media.

Highlights

IntroductionSolar and wind powers are encouraging electricity production technologies for promoting a renewable and clean energy organization
Transmission electron microscopy (TEM) of the BI15 NPs showed a nanostructure consisting of blue TiO2 NPs (20–30 nm size) with uniform dots on the surface (Figure 1c)
This study demonstrated a feasible method to modify the surface of blue TiO2 nanoparticles with IrO2 nanoclusters (Ir–O2 –2Ti NPs) in the presence of borohydride as a reducing agent at room temperature

Summary

Introduction

Solar and wind powers are encouraging electricity production technologies for promoting a renewable and clean energy organization. The discontinuous convenience of solar and wind powers critically encumber their wide variety of applications. Efficient and accessible means for storing energy are demanded to bridge the gap between supply and requirement [1,2]. Hydrogen (H2 ) generated from the electrocatalytic water splitting (EWS) could feed such a long-time energy storage system due to the high density of gravimetric energy. The EWS is an important step for reaching renewable H2 energy storage. The oxygen evolution reaction (OER), as one of the half-reactions in EWS, is a complicated transfer reaction of multi-electron, which includes a high overpotential to the actual reactive route, leading to a significant reduction of the reaction performance [3,4]

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