Phosphorus Incorporation into Co₉S₈ Nanocages for Highly Efficient Oxygen Evolution Catalysis

Abstract

The improvement of activity of electrocatalysts lies in the increment of the density of active sites or the enhancement of intrinsic activity of each active site. A common strategy to realize dual active sites is the use of bimetal compound catalysts, where each metal atom contributes one active site. In this work, a new concept is presented to realize dual active sites with tunable electron densities in monometal compound catalysts. Dual Co2+ tetrahedral (Co2+(Td)) and Co3+ octahedral (Co3+(Oh)) coordination active sites are developed and adjustable electron densities on the Co2+(Td) and Co3+(Oh) are further achieved by phosphorus incorporation (P‐Co9S8). The experimental results and density functional theory calculations show that the nonmetal P doping can systematically modulate charge density of Co2+(Td) and Co3+(Oh) in P‐Co9S8 and simultaneously improve the electrical conductivity of Co9S8, which substantially enhances oxygen evolution reaction performance of P‐Co9S8.

A Ternary Dumbbell Structure with Spatially Separated Catalytic Sites for Photocatalytic Overall Water Splitting

“…The high resolution XPS signal (Figure 3b) of S 2p can be well deconvoluted into two separate peaks located at 162.8 and 161.6 eV, corresponding to S 2p 1/2 and S 2p 3/2 in the form of S 2− , respectively. [ 39,40 ] The high resolution Ru 3p XPS spectrum (Figure 3c) exhibits the doublets for Ru 3p 1/2 and Ru 3p 3/2 peaks at 484.5 and 461.7 eV, respectively, as expected for RuO 2 . [ 41 ] With regard to the XPS spectrum of O 1s (Figure 3d), two discrete peaks at 530.9 and 531.9 eV are indexed to RuORu and RuOH, and the other one at 532.8 eV is attributed to CO bond, which originates from the surface oxygenated groups.…”

Boosting Transport Kinetics of Cobalt Sulfides Yolk–Shell Spheres by Anion Doping for Advanced Lithium and Sodium Storage

“…Recently, transition-metal sulfides (TMSs) have been widely used as anode materials in LIBs and SIBs owing to their excellent electronic conductivity, high theoretical capacity, and abundant redox chemical properties. [8,13,[15][16][17][18] Among them, Co and S can be combined to form various forms of compounds with different valence states such as CoS, [19][20][21] CoS 2 , [22][23][24] Co 3 S 4 , [13,25,26] Co 9 S 8 , [27][28][29] and others, which endows them as potential anode materials with high theoretical specific capacity and superior thermal stability. However, the issues of rapid capacity decay, poor reaction kinetics, and severe polarization owing to volume changes during electrochemical reactions are still huge challenges for cobalt sulfides in practical applications.…”

Two‐Dimensional NiIr@N‐Doped Carbon Nanocomposites Supported on Ni Foam for Electrocatalytic Overall Water Splitting

“…[1][2][3][4] Thew ater splitting reaction, composed of the hydrogen evolution reaction (HER) at the cathodea nd oxygen evolution reaction( OER) at the anode, is at hermodynamically uphill process with high overpotentials. [5][6][7][8] To this end, highly effective electrocatalysts are required to accelerate the reactionk inetics of the HER andO ER. One promising strategy in the developmento fh ighly effective electrocatalysts is to integrate the merits of both HER and OER electrocatalysts to construct HER-OER bifunctional electrocatalysts.…”

“…The electrolysis of water is a feasible avenue for the production of high‐purity hydrogen [1–4] . The water splitting reaction, composed of the hydrogen evolution reaction (HER) at the cathode and oxygen evolution reaction (OER) at the anode, is a thermodynamically uphill process with high overpotentials [5–8] . To this end, highly effective electrocatalysts are required to accelerate the reaction kinetics of the HER and OER.…”