Polyoxometalate‐Derived Ir/WO_x/rGO Nanocomposites for Enhanced Electrocatalytic Water Splitting

Abstract

Iridium (Ir)-based nanomaterials are promising electrocatalysts for water splitting, and to alleviate their costs as well as improve the performances are always important tasks. Polyoxometalates (POMs) composed of abundant metal, oxygen, and heteroatoms are nanoclusters with defined structures. Benefitting from the inherent advantages of POMs, highly dispersive and "unprotected" Ir nanoparticles originating from Ir-based colloid solution were successfully anchored on POM-derived WO 3 /rGO nanocomposites for the first time. Interestingly, the obtained hybrid material Ir/WO x /rGO delivered improved electrocatalytic performance for water splitting, which is attributed to the addition of only quite small amount of POM derivatives. This work is also the first proof that POM can be employed as precursor to construct metal oxides to support Ir catalysts, providing a new vision for the design of advanced multi-metal electrocatalysts. COMMUNICATION Water Splitting

Development of IrO2–WO3 Composite Catalysts from Waste WC–Co Wire Drawing Die for PEM Water Electrolyzers’ Oxygen Evolution Reactions

“…The OER kinetic performances of catalysts with different W compositions are determined in the following order: IW-75 > IW-50 > IrO 2 > WO 3 , indicating an essential enhancement of OER performance for W-rich-based catalysts. According to the BET surface analysis results of the catalysts (Table ), this improvement may result from an increase in electrochemical performance due to the higher surface areas of the catalysts . As seen in LSV curves between 1.2 and 1.6 V, the highest current density is achieved in the line of IW-75 > IW-50 > IrO 2 > WO 3 .…”

Application of polyoxometalates in photocatalytic degradation of organic pollutants

“…Compared with the traditional metal composites, the nanoparticles prepared through POM precursors have several advantages: i) the structure of POM precursor is defined and can be designed at an atomic scale; ii) the derivatives are nanostructure and can be rationally controlled; iii) the inherent heteroatoms can be directly doped into the lattices of metal nanocomposites for band gap regulation; iv) the agglomeration problem of traditional metal composites can be alleviated because there are steric hindrances and electronic repulsion between the POM precursors, ensuring the high dispensability during the synthetic procedure. [127,128] Recently, some researchers have utilized these nanoparticles as photocatalysts for efficient photocatalytic degradation of organic pollutants in wastewater. [129] It is a new promising direction that employing POMs as precursor materials to achieve highly efficient nanophotocatalysts.…”

Mitigation of RuO6 octahedron distortion by enhanced A-site electronegativity in pyrochlore for acidic water oxidation

“…[5][6][7] Unfortunately, the slow kinetics of the anodic oxygen evolution reaction (OER) limits the efficiency of the overall reaction. [8][9][10][11] High oxidation voltage coupled with strong acid media creates a harsh operating environment, where only expensive IrO 2 is currently used for commercial applications. [12][13][14][15][16] Compared with iridium oxide, ruthenium oxide has higher intrinsic activity and lower cost, but unsatisfactory stability.…”