Cation‐Modulated HER and OER Activities of Hierarchical VOOH Hollow Architectures for High‐Efficiency and Stable Overall Water Splitting

Abstract

Atom‐scale modulation of electronic regulation in nonprecious‐based electrocatalysts is promising for efficient catalytic activities. Here, hierarchically hollow VOOH nanostructures are rationally constructed by partial iron substitution and systematically investigated for electrocatalytic water splitting. Benefiting from the hierarchically stable scaffold configuration, highly electrochemically active surface area, the synergistic effect of the active metal atoms, and optimal adsorption energies, the 3% Fe (mole ratio) substituted electrocatalyst (VOOH‐3Fe) exhibits a low overpotential of 90 and 195 mV at 10 mA cm−2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline media, respectively, superior than the other samples with a different substituted ratio. To the best of current knowledge, 195 mV overpotential at 10 mA cm−2 is the best value reported for V or Fe (oxy)hydroxide‐based OER catalysts. Moreover, the electrolytic cell employing the VOOH‐3Fe electrode as both the cathode and anode exhibits a cell voltage of 0.30 V at 10 mA cm−2 with a remarkable stability over 60 h. This work heralds a new pathway to design efficient bifunctional catalysts toward overall water splitting.

Ionic Liquid‐Intercalated Metallic MoS2 as a Superior Electrode for Energy Storage Applications

“…[3] For example, photo catalytic, electrochemical and photo electrochemical systems are designed to produce Hydrogen gas using the water splitting reaction. [4][5][6][7][8] Among them electrochemical hydrogen generation from water considered to be effective renewable energy source to convert the electrical energy into chemical energy and stored as a green fuel. [9] Till date, platinum is the best electro-catalyst to generate the hydrogen gas by water-splitting reaction in the acidic medium.…”

“…As a result, alternative energy conversion and storage systems have been developed to overcome the energy crisis . For example, photo catalytic, electrochemical and photo electrochemical systems are designed to produce Hydrogen gas using the water splitting reaction . Among them electrochemical hydrogen generation from water considered to be effective renewable energy source to convert the electrical energy into chemical energy and stored as a green fuel .…”

Stimuli‐responsive photofunctional materials for green and security printing

“…11,12 During the recycling of paper waste, the fiber in the paper can only be recovered 2.4 times on average. 6,[13][14][15][16][17][18] The development of functional papers that can reuse multiple times in a "writing-erasing-writing" cycle is an effective way to solve these problems and achieve green printing. In addition, in the era of information explosion, there is a growing demand for paper document security since information leakage brings enormous security issues.…”

Two‐Phase Colloidal Synthesis of Amorphous Iron‐Doped Manganese Phosphate Hollow Nanospheres for Efficient Water Oxidation

“…[ 15–18 ] Specifically, constructing hollow nanostructures especially hollow nanospheres would be beneficial to the increased specific surface area and accelerated charge transfer ability between active sites and intermediates, which is regarded as a feasible route to develop excellent OER catalysts. [ 19–22 ] For example, Wang and co‐workers reported the synthesis of lepidocrocite VOOH hollow nanospheres and their good OER activity with overpotential of 270 mV at 10 mA cm −2 . [ 21 ] Moreover, it is reported that some amorphous materials exert outstanding catalytic property than their crystalline counterparts, meaning the rational design amorphous catalysts is another attractive method to further promote OER activity.…”