Engineering Ternary Pyrite‐Type CoPS Nanosheets with an Ultrathin Porous Structure for Efficient Electrocatalytic Water Splitting

Abstract

For electrochemical water splitting, the development of lowcost, efficient, and robust electrocatalysts for both the oxygen evolution reaction and hydrogen evolution reaction remains challenging. Herein, we report stoichiometric ternary-phase CoPS with a two-dimensional ultrathin porous nanosheet structure as an efficient bifunctional electrocatalyst for overall water splitting. Owing to the stable stoichiometric ternary phase, abundant octahedral Co 3 + is observed in CoPS, serving as active sites to boost electrocatalytic activities. With the introduction of the ultrathin porous nanosheet structure, more active sites are exposed to enhance the electrochemical performance. Therefore, the samples display remarkable oxygen evolution activity with a low overpotential of 316 mV at 10 mA cm À 2 and a small Tafel slope of 50.2 mV dec À 1 . Combined with their highly efficient hydrogen evolution activity, CoPS ultrathin porous nanosheets are demonstrated to have extraordinary activities for overall water splitting, with a cell voltage of 1.57 V to reach 10 mA cm À 2 current density. This work not only provides a bifunctional catalyst with outstanding performance, but also offers a facile route for improving electrocatalytic activity by synergistic morphology design and electronic modulation.

Co(OH)2 Nanosheets Array Doped by Cu2+ Ions with Optimal Electronic Structure for Urea‐Assisted Electrolytic Hydrogen Generation

“…The XRD pattern of Cu 6.2% −Co(OH) 2 exhibited no new phase emerged (Figure S6b). The XPS spectrum of Co 2p presented two new peaks at 780.1 and 795.5 eV (Figure S6c), which were corresponded to Co 3+ on account of CoOOH formation by the slight surface oxidation of Cu 6.2% −Co(OH) 2 under strong alkali circumstances [41,42] . The O 1s XPS spectrum displayed a new peak at 529.5 eV (Figure S6d), which could be accredited to the lattice oxygen species of CoOOH [41,43] .…”

“…The XPS spectrum of Co 2p presented two new peaks at 780.1 and 795.5 eV (Figure S6c), which were corresponded to Co 3 + on account of CoOOH formation by the slight surface oxidation of Cu 6.2% À Co(OH) 2 under strong alkali circumstances. [41,42] The O 1s XPS spectrum displayed a new peak at 529.5 eV (Figure S6d), which could be accredited to the lattice oxygen species of CoOOH. [41,43] The Cu 2p XPS spectrum was barely changed (Figure S6e), indicating the same oxidation state of Cu atoms with that of the initial catalyst.…”

Fe‐Doped Ni3S2 Nanowires with Surface‐Restricted Oxidation Toward High‐Current‐Density Overall Water Splitting

“…The Lewis acidity is enhanced by the charge delocalization via d‐d overlapping of cations . It promotes water adsorption and activation, and increases the electrophilicity of the adsorbed O and subsequent O−OH formation through nucleophilic attack, which also probably boosts the deprotonation of the OOH species to produce O 2 by electron‐withdrawing induction effect . Furthermore, the charge delocalization of cations can provide accessible donor‐receptor chemisorption sites for O 2 reversible adsorption .…”

Synthesis of Graphitic Carbon Coated ZnPS3 and its Superior Electrochemical Properties for Lithium and Sodium Ion Storage

“…The previously reported MPS 3 /carbon composites were the mixtures of MPS 3 particles and carbon matrix and no carbon-coated MPS 3 has been reported yet. [25][26][27] In this study, ZnPS 3 powder was synthesized by a direct phosphosulfurization process [55] and ZnPS 3 /carbon composite was prepared by a high energy mechanical milling (HEMM) method using as-synthesized ZnPS 3 and multiwall carbon nanotubes (MWCNTs). As-prepared materials were introduced as anodes for both LIBs and SIBs and their electrochemical properties were investigated for the first time, particularly focusing on the electrochemical reaction mechanism and cycling performance.…”