Hierarchical Mesoporous MXene–NiCoP Electrocatalyst for Water-Splitting

Abstract

The utilization of nonprecious metal electrocatalysts for water-splitting may be the ultimate solution for sustainable and clean hydrogen energy. MXene, an emerging two-dimensional material, exhibits many unique properties such as possible metal-like conductivity, hydrophilic surface, and rich chemistry, rendering a group of promising catalysts and catalyst support materials. In this study, exfoliated Ti3C2 MXenes serve as a substrate to perpendicularly grow uniform mesoporous NiCoP nanosheets through an in situ interface-growth strategy and subsequent phosphorization. The obtained Ti3C2@mNiCoP materials with a stable hierarchical sandwich structure possess excellent conductivity, large surface area, and uniform mesopores with high pore volume. With these beneficial properties, the Ti3C2@mNiCoP material exhibits superior overall water-splitting performance compared with that of its building-block counterparts, matching the state-of-the-art water-splitting electrocatalysts.

Nitrogen-Doped Mesoporous Carbon Microspheres by Spray Drying-Vapor Deposition for High-Performance Supercapacitor

“…The invagination zones on the granules are probably caused by temperature (Biswas et al, 2016 ) and/or the polydispersity of constituent nanoparticles (Sen et al, 2012 ) during rapid spray drying. It is reported that the spherical morphology exhibits a higher packing density compared to other morphologies because the packing voids from large spheres accommodate smaller ones (Ying et al, 2004 ; Pan et al, 2020 ; Yue et al, 2020a , b ). For comparison, MC-7-AD and MC-7-FD show fragmented morphologies with random particle packing ( Figures 2b,c ), leading to lower packing densities.…”

“…A shoulder peak at 2–5 nm can also be observed. Unlike MC-7-AD and MC-7-FD, MC-7-SD shows a wide PSD in the range of 2–9 nm, which can be attributed to the small mesoporous packing voids in the microspheres (Ying et al, 2004 ; Pan et al, 2020 ; Yue et al, 2020a , b ).…”

Recent Advances in Functional 2D MXene‐Based Nanostructures for Next‐Generation Devices

“…[185] Apart from extensively photocatalytic applications, functional 2D MXenes also play an important role in the field of electrocatalysis due to the unique features, such as high surface area, excellent conductivity, suitable hydrophilicity, and good chemical stability. [192][193][194][195][196][197] In 2019, Ramalingam et al [194] reported the coordination interaction between ruthenium single atoms (Ru SA ) and 2D MXene Ti 3 C 2 T x through N and S heteroatom doping. The hydrogen evolution reaction (HER) polarization curves of bare carbon paper (CP); Ti 3 C 2 T x ; N and S co-doped Reproduced with permission.…”

“…[201] The turnover frequency (TOF) values of the Ru SA -N-S-Ti 3 C 2 T x electrocatalyst are superior or comparable with transition metal-based HER electrocatalysts in acidic electrolyte (Figure 11c), confirming its exceptional activity. Moreover, Yue et al [192] introduced mesoporous NiCoP (mNiCoP) into MXene Ti 3 C 2 to fabricate 2D sandwich structures (Ti 3 C 2 @mNiCoP) for electrocatalytic water-splitting. The HER polarization curve of Ti 3 C 2 @mNiCoP heterostructure displays an overpotential of 127 mV at a current density of 10 mA cm −2 (Figure 11d), which is remarkably smaller than those of rGO@ mNiCoP (196 mV) and mNiCoP (209 mV).…”

Increasing Electrocatalytic Oxygen Evolution Efficiency through Cobalt‐Induced Intrastructural Enhancement and Electronic Structure Modulation

“…The raw materials needed for EWS are not only abundantly available, but energy conversion from electrical to chemical energy can also effectively fill the large gaps in energy supply requirements [7–10] . However, as an indispensable half‐reaction in EWS systems, the oxygen evolution reaction (OER) at the anode involves a multi‐electron transfer process with a high electrochemical energy barrier; it thus requires an advanced electrocatalyst to accelerate the sluggish kinetics of the overall reaction [11–14] . Although noble‐metal Ir/Ru‐based materials are considered as benchmark OER catalysts, they are extremely scarce, and exorbitant market prices severely impede their commercial application.…”