Hierarchically Porous W‐Doped CoP Nanoflake Arrays as Highly Efficient and Stable Electrocatalyst for pH‐Universal Hydrogen Evolution

Abstract

It is still challenging to develop high‐efficiency and low‐cost non‐noble metal‐based electrocatalysts for hydrogen evolution reaction (HER) in pH‐universal electrolytes. Herein, hierarchically porous W‐doped CoP nanoflake arrays on carbon cloth (W‐CoP NAs/CC) are synthesized via facile liquid‐phase reactions and a subsequent phosphorization process. The W‐CoP NAs/CC hybrid can be directly employed as a binder‐free electrocatalyst and delivers superior HER performance in pH‐universal electrolytes. Especially, it delivers very low overpotentials of 89, 94, and 102 mV to reach a current density of 10 mA cm–2 in acidic, alkaline, and neutral electrolytes, respectively. Furthermore, it shows a nearly 100% Faradaic efficiency as well as superior long‐term stability with no decreasing up to 36 h in pH‐universal electrolytes. The outstanding electrocatalytic performance of W‐CoP NAs/CC can be mainly attributed to the porous W‐doped nanoflake arrays, which not only afford rich exposed active sites, but also accelerate the access of electrolytes and the diffusion of H2 bubbles, thus efficiently promoting the HER performance. This work provides a new horizon to rationally design and synthesize highly effective and stable non‐noble metal phosphide‐based pH‐universal electrocatalysts for HER.

Etching‐Doping Sedimentation Equilibrium Strategy: Accelerating Kinetics on Hollow Rh‐Doped CoFe‐Layered Double Hydroxides for Water Splitting

“…Considering these results, the reaction process driven by Rh doped CoFe-ZLDH follows the Volmer-Heyrovsky mechanism to achieve a rapidly increasing hydrogen evolution rate under the application of voltage. As shown in Figure 3c and Table S2 in the Supporting Information, Rh-doped CoFe-ZLDH outperforms many other previously reported state-of-art HER electrocatalysts, such as Rh 2 P, [41] L-Ag, [42] single atomic Co supported on phosphorized carbon nitride nanosheets (Co 1 /PCN), [43] NiMoO x -Ni(OH) 2 /NF, [44] interface catalyst consisting of atomic cobalt array covalently bound to distorted 1T MoS 2 nanosheets (SA Co-D 1T MoS 2 ), [45] Pt clusters in hollow mesoporous carbon spheres (Pt 5 /HMCS), [46] Ni-Fe nanoparticle (Ni-Fe NF), [39] oxygen vacancy enrich CoFe 2 O 4 (r-CFO), [47] CoFeP TAPs/Ni, [48] nickel-molybdenum-nitride nanoplates on carbon fiber cloth (Ni-Mo-N/CFC), [40] Ru SA -N-S-Ti 3 C 2 T x , [9] W-CoP NAs-CC, [49] MoP@NCHs-900, [50] Co 9 S 8 @C, [51] and Co 0.31 Mo 1.69 C/MXene/NC. [52] The cyclic voltammetry (CV) method was utilized to calculate the electrochemical double-layer capacitance (C dl ) to reflect the electrochemical active area (ECSA).…”

Phosphorus‐Based Electrocatalysts: Black Phosphorus, Metal Phosphides, and Phosphates

“…[ 77 ] Further, in the case of Ru‐doped CoP, not only can the doping of Ru into the CoP structure modulate the electronic structure, but also resulted in the reduced particle sizes and the increased specific surface area, which had benefited to exposing more active sites. [ 124 ] Based on the doping tactics, W‐doped, [ 125 ] Cu‐doped, [ 126 ] and Ce‐doped [ 127 ] cobalt phosphides, Co‐doped WP [ 128 ] were synthesized, where the metal dopant improves the conductivity, increases the active sites, gives rise to a coordinative effect of enhancing water dissociation and optimizing hydrogen adsorption, and consequently facilitates the HER, as shown by experimental validation and/or theoretical computations. Furthermore, trimetallic phosphides, including Fe x Co y Ni z P [ 129 ] and WNiCoP, [ 130 ] have been successfully prepared for efficacious hydrogen generation, where the synergistic effects appear to be more complex.…”

3D ordered mesoporous cobalt ferrite phosphides for overall water splitting

“…Transition metal (Co, Ni, Fe, Mn) oxides [8], sulfides [9][10][11], phosphides [12,13], selenides [14,15], and perovskites [16] have been exploited as electrocatalysts for water electrolysis and impressive progress has been achieved. Particularly, transition metal phosphides attract more attention attributed to their low cost, natural abundance, and superior catalytic performance [17][18][19][20][21]. Compared with mono-metal phosphides, bi-metal phosphides have been proved to show richer faradaic redox and higher electrical conductivity and stability owing to their electronic structure optimization and synergistic effect [22][23][24].…”