Rational design of highly efficient bifunctional electrocatalysts based on 3D transition-metal-based materials for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is of great importance for sustainable energy conversion processes. Herein, a novel strategy involving outer and inner structural engineering is developed for superior water splitting via in situ vertical growth of 2D amorphous FePO nanosheets on Ni foam (Am FePO /NF). Careful experiments and density functional theory calculations show that the inner and outer structural engineering contributing to the synergistic effects of 2D morphology, amorphous structure, conductive substrate, and Ni-Fe mixed phosphate lead to superior electrocatalytic activity toward OER and HER. Furthermore, a two-electrode electrolyzer assembled using Am FePO /NF as an electrocatalyst at both electrodes gives current densities of 10 and 100 mA cm at potentials of 1.54 and 1.72 V, respectively, which is comparable to the best bifunctional electrocatalyst reported in the literature. The strategies, introduced in the present work, may open new opportunities for the rational design of other 3D transition-metal-based electrocatalyst through an outer and inner structural control to strengthen the electrocatalytic performance.

We present a one-pot colloidal route to synthesize VSe2, a new type of metallic single-layer nanosheet. The ∼0.4 nm thick VSe2 single-layer nanosheets possess extraordinary electrocatalytic hydrogen evolution reaction (HER) performance with a low onset overpotential of 108 mV, a small Tafel slope of 88 mV per decade, and an exceptional overpotential of 206 mV at a current density of 10 mA cm(-2).

Amorphous micro/nanomaterials are very important members of the noncrystalline materials family and have attracted tremendous interest and exhibited their excellent performance in the application of electrical catalysis and energy storage. The complexity of this research field is limited ultimately by the lack of a facile and practicable strategy to synthesize well-defined ultrathin amorphous nanomaterials. Here, for the first time, we report the random attachment of Co 3 (PO 4 ) 2 amorphous nanoplate building blocks into ultrathin nanosheets with dimensions on the micrometer scale. We found the structure of obtained Co 3 (PO 4 ) 2 amorphous nanosheet can be converted into nanowire by a split process. On the basis of our observations, an assemble-split mechanism for synthesizing ultrathin amorphous nanostructure is proposed. Furthermore, our strategy is general and can be used to prepare other metal phosphate amorphous ultrathin nanostructures. As a demonstration, the synthesized Co 3 (PO 4 ) 2 ultrathin nanowire has been proven to show extraordinary performance as an electrode material for a pseudocapacitor with the specific capacitance of up to 1174 F g −1 , which is much higher than that of crystalline cobalt phosphate and even comparable to that of cobaltous hydroxide nanomaterials.

Hydrogel thin films with embedded 3-D ordered colloidal nanoparticle arrays are fabricated and functionalized with spatially distributed thiol groups for high-sensitive and selective detection of trace Hg2+ ions in seawater.

Colloidal Mn-doped CsPb(Cl/Br)3 NCs were synthesized at different MnCl2-to-PbBr2 molar feed ratios or reaction temperatures to tune their color emission.