Caged-Cation-Induced Lattice Distortion in Bronze TiO₂for Cohering Nanoparticulate Hydrogen Evolution Electrocatalysts

Abstract

Defect engineering provides a promising approach for optimizing the trade-off between support structures and active nanoparticles in heterojunction nanostructures, manifesting efficient synergy in advanced catalysis. Herein, a high density of distorted lattices and defects are successfully formed in bronze TiO 2 through caging alkali-metal Na cations in open voids (Na-TiO 2 (B)), which could efficiently cohere nanoparticulate electrocatalysts toward alkaline hydrogen evolution reaction (HER). The RuMo bimetallic nanoparticles could directionally anchor on Na-TiO 2 (B) with a certain angle of ∼22°due to elimination of the lattice mismatch, thus promoting uniform dispersion and small sizing of supported nanoparticles. Moreover, caging Na ions could significantly enhance the hydrophilicity of the substrate in RuMo/Na-TiO 2 (B), leading to the strengthening synergy of water dissociation and hydrogen desorption. As expected, this Na-caged nanocomposite catalyst rich with structural perturbations manifests a 6.4-fold turnover frequency (TOF) increase compared to Pt/C. The study provides a paradigm for designing stable nanoheterojunction catalysts with lattice-distorted substrates by caging cations toward advanced electrocatalytic transformations.

Enhanced interaction between Ru nanoparticles and N, C-modified mesoporous TiO2for efficient electrocatalytic hydrogen evolution at all pH values

“…In addition, the synergetic catalytic effect of Ru and N-TiO 2 /C exists under all pH conditions. Based on previous literature reports, [54][55][56][57][58][59] in neutral and alkaline electrolytes, Ru@N-TiO 2 /C has high adsorption strength towards H 2 O molecules. And this can boost the water dissociation into H + and OH − , which are then respectively captured by negative-charged N-TiO 2 /C and positive-charged Ru sites in neutral or alkaline electrolytes (eqn (1) and ( 2)).…”

Intermetallic ferric nickel silicide alloy derived from magadiite by magnesiothermic reaction as bifunctional electrocatalyst for overall water splitting

“…What is worth mentioning, although the specific surface area of FeSi is slightly larger than FeNiSi, the subsequent pore size distribution (Fig. 3(b)) shows that FeNiSi has more mesoporous structures which are beneficial for the mass transfer and oxygen diffusion [48,49]. All above results indicate that the as-synthesised intermetallic silicide alloys possess considerable specific surface area and rich pore structure.…”

Oxygen Bridge Formed by Doping Nonmetal Atoms into Cationic Vacancies To Enhance the Photoelectrochemical Oxygen Evolution Reaction

“…With abundant storage, low cost, good stability, nontoxicity, and efficient photocatalytic activity, TiO 2 has attracted considerable attention for photoelectrochemical (PEC) water splitting in renewable energy conversion. − However, PEC water splitting of TiO 2 is still limited by low electronic mobility, bulk recombination of photogenerated carriers, sluggish hole transfer kinetics, and a poor visible-light response. − To solve the above problems, many effective strategies, such as introduction of vacancies, heterojunction construction, element doping, and surface sensitization with visible-light active species, have been rapidly developed for enhancing catalytic activity. − In particular, doping elements into vacancies with reducing bandgaps has been widely applied for PEC water splitting. − However, another strategy to modulate electronic structures without changing bandgap is rarely explored.…”