Boosting hydrogen production with ultralow working voltage by selenium vacancy‐enhanced ultrafine platinum–nickel nanowires

Abstract

Defect engineering provides a highly potential way to yield exceptional catalytic performance. Herein, we first report the selenium (Se) vacancies‐decorated ultrafine platinum–nickel (PtNi‐Sev) nanowires, as a bifunctional catalyst for the hydrogen evolution reaction (HER) and methanol oxidation reaction (MOR). The optimized PtNi‐Sev exhibits obvious enhancement for HER and MOR compared to PtNi nanowires. It displays merely an overpotential of 18.8 mV for alkaline HER and the outstanding MOR performance (3.51 A/mgPt). When applying in one symmetric overall water splitting electrolyzer coupling with HER and MOR, an ultralow working voltage of 0.637 V with 100% Faraday efficiency for hydrogen production was achieved at the current density of 10 mA/cm2. Further investigations reveal that the weakened hydrogen binding energy, strong OH binding as well as relative weak CO binding are responsible for the improved HER and MOR activities.

Preparation of Flower-Shaped Co-Fe Layer Double Hydroxide Nanosheets Loaded with Pt Nanoparticles by Corrosion Engineering for Efficient Electrocatalytic Water Splitting

“…It is well-established that the free energy (Δ G H* ) of hydrogen adsorption on the catalyst surface is of paramount importance for HER . In addition, the adsorption of OH* as another prerequisite could facilitate water dissociation in alkaline conditions.…”

“…It is well-established that the free energy (ΔG H* ) of hydrogen adsorption on the catalyst surface is of paramount importance for HER. 37 In addition, the adsorption of OH* as another prerequisite could facilitate water dissociation in alkaline conditions. Therefore, the optimal OH* adsorption represents an effective pathway for boosting the water dissociation reaction (Volmer reaction).…”

Onset Potential Shift of Water Oxidation in the Metastable Phase Transformation Process of β-Fe2O3

“…The process of solar water splitting requires photoanode materials with suitable band gaps and excellent stability. − Iron oxide (Fe 2 O 3 ) is considered to be the photoanode material that has the most potential application possibility. α-Fe 2 O 3 is the most thermodynamically stable phase among the four phases of Fe 2 O 3 (α, β, γ, and ε) and has been studied as a traditional photoanode material in the past few decades. − Researchers have spent a great deal of effort on the factors that limit its photoelectrochemical performance and have proposed methods to solve these problems. − The saturation photocurrent density of the α-Fe 2 O 3 photoanode can reach 4 mA cm –2 , and the onset potential can be reduced to 0.6 V RHE . − This performance is still far from its practical application in photoelectrochemical cells.…”

Boosting the oxygen evolution electrocatalysis of high-entropy hydroxides by high-valence nickel species regulation

“…1,2 Unfortunately, the kinetically sluggish four proton-electron coupled process of the OER is the Gordian knot and greatly impairs the energy conversion efficiency, urgently requiring highly efficient earth-abundant transition metal-based electrocatalysts. 3,4 Up to now, Ni-based materials stand out from the crowd as advanced electrocatalysts for the OER. Moreover, according to the principle proposed by Shao-Horn requiring an e g occupancy close to unity, the electronic configuration of t 2g 6 e g 1 of the Ni 3+ site can promote the covalency of transition metal-oxygen bonds, thereby boosting the OER activity.…”

“…1,2 Unfortunately, the kinetically sluggish four proton–electron coupled process of the OER is the Gordian knot and greatly impairs the energy conversion efficiency, urgently requiring highly efficient earth-abundant transition metal-based electrocatalysts. 3,4…”