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Hydrogen is considered a promising clean energy vector with the features of high energy capacity and zero-carbon emission. Water splitting is an environment-friendly and effective route for producing high-purity hydrogen, which contains two important half-cell reactions, namely, the anodic oxygen evolution reaction (OER) and the cathodic hydrogen evolution reaction (HER). At the heart of water splitting is high-performance electrocatalysts that efficiently improve the rate and selectivity of key chemical reactions. Recently, perovskite oxides have emerged as promising candidates for efficient water splitting electrocatalysts owing to their low cost, high electrochemical stability, and compositional and structural flexibility allowing for the achievement of high intrinsic electrocatalytic activity. In this review, we summarize the present research progress in the design, development, and application of perovskite oxides for electrocatalytic water splitting. The emphasis is on the innovative synthesis strategies and a deeper understanding of structure–activity relationships through a combination of systematic characterization and theoretical research. Finally, the main challenges and prospects for the further development of more efficient electrocatalysts based on perovskite oxides are proposed. It is expected to give guidance for the development of novel non-noble metal catalysts in electrochemical water splitting. [ABSTRACT FROM AUTHOR]

Catalysts with multifunctional catalytic properties hold great promise in energy conversion and environmental remediation. Herein, a series of 1D hollow NiO/Bi 2 Mo x W 1−x O 6 (x = 0, 0.25, 0.5, 0.75, 1) nanofibers are fabricated via pyrolysis of electrospinning precursor. Integrating the hollow structural merits of large specific surface area, abundant active sites, and built-in electric field, this novel NiO/Bi 2 Mo x W 1−x O 6 nanofibers act as a bifunctional platform boosting photocatalytic tetracycline conversion and electrocatalytic oxygen reduction. NiO/Bi 2 Mo 0.75 W 0.25 O 6 solid solution nanofiber delivers a 99.5 % photocatalytic degradation in 120 min for tetracycline (TC) solution with attractive stability, outperforming its NiO/Bi 2 MoO 6 or NiO/Bi 2 WO 6 counterparts. Radical trapping experiments show that ∙ O 2 ⁻ is the key oxidative radical in the photocatalytic reaction. Moreover, the NiO/Bi 2 Mo 0.75 W 0.25 O 6 solid solution nanofiber exhibits an improved ORR activity in alkaline media with a half-wave potential of 0.63 V, and Tafel slope of 76 mV dec−1, along with high stability. We expect this work to inspire the design of multi-functional catalysts for photocatalytic water treatment and electrocatalytic energy conversion. • 1D NiO/Bi 2 Mo x W 1−x O 6 (x = 0, 0.25, 0.5, 0.75, 1) nanofibers are fabricated via a pyrolysis of electrospinning precursor. • This NiO/Bi 2 Mo x W 1−x O 6 nanofibers act as a bifunctional platform boosting photocatalytic and electrocatalytic reduction. • NiO/Bi 2 Mo 0.75 W 0.25 O 6 solid solution nanofiber delivers a 99.5 % photocatalytic degradation in 120 min for TC solution. • NiO/Bi 2 Mo 0.75 W 0.25 O 6 solid solution nanofiber exhibits an improved ORR activity and high stability in alkaline media. [ABSTRACT FROM AUTHOR]

Given its superior structure, the abundance of surface functional groups, and low cost, cotton fiber filtration paper can be used as the support for hydrogen evolution reaction (HER) and oxygen evolution reaction catalysts (OER) instead of copper foam (CF), nickel foam (NF), or carbon cloth (CC). Herein, the chemical plating method was used to create thin self-supporting electrodes based on cotton fiber filtration paper (FP). The Co-Ni-P amorphous nanospheres can be uniformly dispersed on the self-supporting FP due to its porous structure and oxygen functional groups. The Co-Ni-P/FP electrode has an overpotential as low as 125 mV for HER and 320 mV for OER at the current density of 10 mA cm−2. Additionally, according to density functional theory (DFT) calculations, the Co atom added to the Ni-P nanosphere can lead to considerably more charge accumulation around the Co and Ni active sites, which greatly encourages the HER and OER processes. The novel porous support, FP, provides a fresh way the preparation of self-supporting electrodes. [Display omitted] • Filter paper is used to prepare the self-supporting electrode as the substrate. • The preparation method is simple and the properties are stable. • Rich oxygen-containing functional groups of FP promote deposition and dispersion. • Explore the excellent electrochemical performance of amorphous Co-Ni-P/FP by DFT. [ABSTRACT FROM AUTHOR]