Wei-Qing Huang

Nickel–iron oxyhydroxides are among the most active electrocatalysts, but their sluggish kinetic of oxygen evolution reaction (OER) limits the energy efficiency toward overall water splitting. Here, we present a “cascade electron transfer” strategy through spurring unidirectional electron transfer among different metal sites in Mn-doped FeNiOOH@ FeNiP to boost OER and overall water splitting. The Mn doping induces a cascade electron transfer from Ni to Fe and then to Mn via metal-O-metal bridge, thus promoting the oxidation Ni and Fe centers, which in turn help charge transfer by increasing the covalency between metal-O bonds to optimize the bonding strength between metal and adsorbed oxygen species. Consequently, the optimal Mn–FeNiOOH@ FeNiP delivers a fast OER kinetics (32.1 mV dec À1) along with a low overpotential of 215 mV@ 10 mA cm À2. Benefiting from the synergistic effect of high …

The controllable construction of complex metal–organic coordination polymers (CPs) merits untold scientific and technological potential, yet remains a grand challenge of one‐step construction and modulating simultaneously valence states of metals and topological morphology. Here, a thiocyanuric acid (TCA)‐triggered strategy is presented to one‐step rapid synthesis a double‐crystalline Prussian blue analogue hetero‐superstructure (PBA‐hs) that comprises a Co3[Fe(CN)6]2 cube overcoated with a KCo[Fe(CN)6] shell, followed by eight self‐assembled small cubes on vertices. Unlike common directing surfactants, TCA not only acts as a trigger for the fast growth of KCo[Fe(CN)6] on the Co3[Fe(CN)6]2 phase resulting in a PBA‐on‐PBA hetero‐superstructure, but also serves as a flange‐like bridge between them. By combining experiments with simulations, a deprotonation‐induced electron transfer (DIET …

Both morphology and composition have a great influence on the properties and functions of materials, however, how to rational modulate both of them to achieve their synergistic effects has been a long-standing expectation. Herein, we demonstrate a competitive assembling strategy for the construction of metal-free graphite carbon nitride (CN) homojunctions in which morphology and composition can be easily controlled simultaneously by only changing the ratio of assembly raw materials. These homojunctions are comprised of porous nanotubular S-doped CN (SCN) grafted with CN nanovesicles, which are derived from thermal polycondensation of melamine-thiocyanuric acid (M-T)/melamine-cyanuric acid (M-C) supramolecular hybrid blocks. This unique architecture and component engineering endows the novel SCN–CN homojunction with abundant active sites, enhanced visible trapping ability, and intimate …

The emergence of metamaterials and their continued prosperity have built a powerful working platform for accurately manipulating the behavior of electromagnetic waves, providing sufficient possibility for the realization of metamaterial absorbers with outstanding performance. However, metamaterial absorbers composed of metallic materials typically possess many unfavorable factors, such as non‐adjustable absorption, easy oxidation, low‐melting, and expensive preparation costs. The selection of dielectric materials provides excellent alternatives due to their remarkable properties, thus dielectric‐based metamaterial absorbers (DBMAs) have attracted much attention. To promote breakthroughs in DBMAs and guide their future development, this work systematically and deeply reviews the recent research progress of DBMAs from four different but progressive aspects, including physical principles; classifications …

Spin plays a key role in physical and chemical reactions, such as oxygen evolution and hydrogen evolution reactions (OER/HER), but the spin–activity correlation has remained unclear. Based on a transition metal (TM)-doped PtN2 monolayer model with a well-defined spin center as an adsorption site, we here reveal that only an active spin state can enhance the strength of hydrogen adsorption, while an inert spin state offers very little influence. Specifically, the an unpaired electron along the out-of-plane direction such as in the dz2 orbital, acting as an active spin state, will strongly hybridize with hydrogen, resulting in enhanced hydrogen binding energy because the dz2 orbital is just enough to accommodate two electrons to form a bonding orbital. While the in-plane unpaired electron such as in the dx2Ày2 orbital plays a negligible role in an adsorbing hydrogen atom. This is verified by a series of single atom …

Surface reconstruction that produces real active species for catalytic reactions generally occurs during electrocatalytic water splitting, but overcoming the reconstruction level‐mass activity‐stability trade‐off is a grand challenge. A cation‐doping in conjunction with a geometrical topology strategy is proposed to concurrently realize deep reconstruction and self‐optimization of FeNi phosphide nanoarrays during an electrochemical activation process. The doped Zn cation induces a deep reconstruction of FeNiP@Fe2P precatalyst by continuously dissolving Fe2P and re‐depositing as amorphous FeOOH that solders Ni2P nanoparticles, forming small ultra‐thin nanosheets with abundant amorphous‐crystalline interfaces for structural stability. Moreover, multichannel topology exhibits an unusual ability to optimize their morphology via finally evolving into multi‐microchannel tubular nanoarrays comprising of …

The rational design of electrocatalysts with well-designed compositions and structures for the oxygen evolution reaction (OER) is promising and challenging. Herein, we developed a novel strategy – a one-step double-cation etching sedimentation equilibrium strategy – to synthesize amorphous hollow Fe-Co-Ni layered double hydroxide nanocages with an outer surface of vertically interconnected ultrathin nanosheets (Fe-Co-Ni-LDH), which primarily depends on the in situ etching sedimentation equilibrium of the template interface. This unique vertical nanosheet-shell hierarchical nanostructure possesses enhanced charge transfer, increased active sites, and favorable kinetics during electrolysis, resulting in superb electrocatalytic performance for the oxygen evolution reaction (OER). Specifically, the Fe-Co-Ni-LDH nanocages exhibited remarkable OER activity in alkaline electrolytes and achieved a current density …

Catalytic performance of single-atom catalysts (SACs) relies fundamentally on the electronic nature and local coordination environment of the active site. Here, based on a machine-learning (ML)-aided density functional theory (DFT) method, we reveal that the intrinsic dipole in Janus materials has a significant impact on the catalytic activity of SACs, using 2D γ-phosphorus carbide (γ-PC) as a model system. Specifically, a local dipole around the active site is a key degree to tune the catalytic activity and can be used as an important descriptor with a high feature importance of 17.1% in predicting the difference of adsorption free energy (ΔGO* – ΔGOH*) to assess the activity of the oxygen evolution reaction. As a result, the catalytic performance of SACs can be tuned by an intrinsic dipole, in stark contrast to those external stimuli strategies previously used. These results suggest that dipole engineering and the …