A universal chemical-induced tensile strain tuning strategy to boost oxygen-evolving electrocatalysis on perovskite oxides

Abstract

Exploring effective, facile, and universal tuning strategies to optimize material physicochemical properties and catalysis processes is critical for many sustainable energy systems, but still challenging. Herein, we succeed to introduce tensile strain into various perovskites via a facile thermochemical reduction method, which can greatly improve material performance for the bottleneck oxygen-evolving reaction in water electrolysis. As an ideal proof-of-concept, such a chemical-induced tensile strain turns hydrophobic Ba5Co4.17Fe0.83O14- δ perovskite into the hydrophilic one by modulating its solid–liquid tension, contributing to its beneficial adsorption of important hydroxyl reactants as evidenced by fast operando spectroscopy. Both surface-sensitive and bulk-sensitive absorption spectra show that this strategy introduces oxygen vacancies into the saturated face-sharing Co-O motifs of Ba5Co4.17Fe0.83O14- δ and transforms such local structures into the unsaturated edge-sharing units with positive charges and enlarged electrochemical active areas, creating a molecular-level hydroxyl pool. Theoretical computations reveal that this strategy well reduces the thermodynamic energy barrier for hydroxyl adsorption, lowers the electronic work function, and optimizes the charge/electrostatic potential distribution to facilitate the electron transport between active sites and hydroxyl reactants. Also, this strategy is reliable for other single, double, and Ruddlesden–Popper perovskites. We believe that this finding will enlighten rational material design and in-depth understanding for many potential applications.

Combined Corner‐Sharing and Edge‐Sharing Networks in Hybrid Nanocomposite with Unusual Lattice‐Oxygen Activation for Efficient Water Oxidation

“…As shown in Figure 5f, the peak intensity of the CoO shell at ≈1.46 Å slightly enhances at 1.75 V versus RHE as compared with the as-prepared sample, which may be ascribed to the adsorption of OHspecies during OER as reported previously. [22,53] Furthermore, the characteristic Co-Co/Fe edgesharing structure (≈2.4 Å) [19,29] and Co-Co/Fe corner-sharing structure (≈3.5 Å) [19,29] of hybrid H-SCF0.55 in the operando Co-K EXAFS spectra are unchanged during OER at 1.75 V versus RHE, confirming its stable local structure.…”

“…Experimentally, we conducted fourier transform infrared spectroscopy (FTIR) measurements to detect the OHadsorption on hybrid H-SCF0.55 after OER. Obviously, the adsorbed OHsignal at ≈3420 cm -1 [53] was observed on hybrid H-SCF0.55 after OER (Figure S18, Supporting Information). Thence, our oxides with more lattice oxygen sites to adsorb OHspecies may tend to induce the LOM catalysis.…”

Entwined Co(OH)2 In Situ Anchoring on 3D Nickel Foam with Phenomenal Bifunctional Activity in Overall Water Splitting

“…Since cobalt is earth abundant, Co-based composites with properties very near to state-of-art catalysts are potential materials to replace Pt/Pd-based catalysts. − The oxygen evolution reaction (OER) (1.23 V) shows severe barrier relative to HER (0 V) owing to sluggish kinetics originating from multistep electron transfer: − OER involved OH – breakage, OH – adsorption, and O–O formation. − Thomas et al . volcano plot (OER) consists of metal oxides based on Δ G O – Δ G OH , where Co-based catalysts are situated at the top, especially spinel-structured metal oxides (MCo 2 O 4 , M–Zn, Fe, Ni, Co, Cu, and Mn).…”

Bio-inspired heterogeneous Fe4S4 single-cluster catalyst for enhanced electrochemical CO2 reduction to CH4

“…4e,4f) for Ni100-Fe 4 S 4 and Ni100-Fe 4 S 4 -*CO 2 , respectively. The work function is an essential physical property of metallic materials 44 , which has been widely used in the design and evaluation of various photo/electrocatalysts 45,46 , can be obtained by calculating the difference between the electrostatic potential at the vacuum level and the oxygen atom has a highly negative charge (-1.76 e and -1.62 e), which means that the most negative charge oxygen atomic site (-1.76 e) is more favorable for the subsequent electrocatalytic step to combine with H + . This selectivity of hydrogenation site is consistent with subsequent Gibbs free energy calculations (Fig.…”