Critical Role of Phosphorus in Hollow Structures Cobalt‐Based Phosphides as Bifunctional Catalysts for Water Splitting

Abstract

Cobalt phosphides electrocatalysts have great potential for water splitting, but the unclear active sides hinder the further development of cobalt phosphides. Wherein, three different cobalt phosphides with the same hollow structure morphology (CoP‐HS, CoP2‐HS, CoP3‐HS) based on the same sacrificial template of ZIF‐67 are prepared. Surprisingly, these cobalt phosphides exhibit similar OER performances but quite different HER performances. The identical OER performance of these CoPx‐HS in alkaline solution is attributed to the similar surface reconstruction to CoOOH. CoP‐HS exhibits the best catalytic activity for HER among these CoPx‐HS in both acidic and alkaline media, originating from the adjusted electronic density of phosphorus to affect absorption–desorption process on H. Moreover, the calculated ΔGH* based on P‐sites of CoP‐HS follows a quite similar trend with the normalized overpotential and Tafel slope, indicating the important role of P‐sites for the HER process. Moreover, CoP‐HS displays good performance (cell voltage of 1.67 V at a current density of 50 mA cm−2) and high stability in 1 M KOH. For the first time, this work detailly presents the critical role of phosphorus in cobalt‐based phosphides for water splitting, which provides the guidance for future investigations on transition metal phosphides from material design to mechanism understanding.

Boosting Hydrogen Evolution Electrocatalysis via Regulating the Electronic Structure in a Crystalline–Amorphous CoP/CeOx p–n Heterojunction

“…The increasingly serious dilemma about the depletion of traditional fossil fuels and its associated environmental pollution is obliging researchers to explore clean, efficient, and sustainable energy sources. Due to its zero-carbon emission and high energy value, H 2 has stood out from the crowd as an ideal alternative energy carrier to tackle environmental issues and energy crises. − Unfortunately, the current technologies for large-scale hydrogen production, such as reforming reaction and biohydrogen process, suffer from mass carbon emission or low conversion efficiency. , Water electrolysis triggered by electricity from solar and wind conversion is an efficient solution to develop a hydrogen economy at no environmental cost. The sluggish kinetics of the cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER) in water splitting seriously limit the rate of hydrogen generation, requiring highly efficient electrocatalysts .…”

Coupling Fe3C Nanoparticles and N‐Doping on Wood‐Derived Carbon to Construct Reversible Cathode for Zn–Air Batteries

“…The construction of specific catalytic sites for water dissociation is an efficient way to accelerate ORR. Varieties of transition metal compounds, including metal carbides, [31][32][33][34][35] sulfides, [36][37][38] nitrides, [34,35,39] phosphides, [40][41][42] and so on, exhibit promising performances in terms of facilitating water dissociation. Particularly, transition metal carbides, such as iron carbide and molybdenum carbide, have attracted special attention due to their noble-metal-like electronic configuration and remarkable catalytic performances in various processes of proton generation from water molecule.…”

Large‐Scale Synthesis of Spinel NixMn3‐xO4 Solid Solution Immobilized with Iridium Single Atoms for Efficient Alkaline Seawater Electrolysis

“…[27][28][29][30] The up-to-date seawater electrocatalysts also basically follow those in water electrolyzers, whereas few can meet the industrially mandated overpotential of 300 mV at 500 mA cm -2 with a cell voltage of below 1.60 V. Besides, apart from the prerequisite OER efficiency and stability, industrial seawater electrolyzer also require the electrocatalysts that can be easily scaled up, which is hardly achieved by template-based synthesis or exfoliation process. [31,32] Therefore, developing innovative seawater electrocatalysts with efficient OER activity and high selectivity, and mass-productive characteristics is of great necessity.…”