This review summarized the fabrication routes and characterization methods of atomic site electrocatalysts (ASCs) followed by their applications for water splitting, oxygen reduction and selective oxidation.

High-efficiency water electrolysis is the key to sustainable energy. Here we report a highly active and durable RuIrOx (x ≥ 0) nano-netcage catalyst formed during electrochemical testing by in-situ etching to remove amphoteric ZnO from RuIrZnOx hollow nanobox. The dispersing-etching-holing strategy endowed the porous nano-netcage with a high exposure of active sites as well as a three-dimensional accessibility for substrate molecules, thereby drastically boosting the electrochemical surface area (ECSA). The nano-netcage catalyst achieved not only ultralow overpotentials at 10 mA cm−2 for hydrogen evolution reaction (HER; 12 mV, pH = 0; 13 mV, pH = 14), but also high-performance overall water electrolysis over a broad pH range (0 ~ 14), with a potential of mere 1.45 V (pH = 0) or 1.47 V (pH = 14) at 10 mA cm−2. With this universal applicability of our electrocatalyst, a variety of readily available electrolytes (even including waste water and sea water) could potentially be directly used for hydrogen production.

Fore lectrocatalysts for the hydrogen evolution reaction (HER), encapsulating transition metal phosphides (TMPs) into nitrogen-doped carbon materials has been known as an effective strategy to elevate the activity and stability.Y et still, it remains unclear how the TMPs work synergistically with the N-doped support, and which Nc onfiguration (pyridinic N, pyrrolic N, or graphitic N) contributes predominantly to the synergy.H ere we present aH ER electrocatalyst (denoted as MoP@NCHSs) comprising MoP nanoparticles encapsulated in N-doped carbon hollows pheres,w hich displays excellent activity and stability for HER in alkaline media. Results of experimental investigations and theoretical calculations indicate that the synergy between MoP and the pyridinic Ncan most effectively promote the HER in alkaline media.

The development of highly active and stable bifunctional noble-metal-based electrocatalysts for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) is a crucial goal for clean and renewable energy, which still remains challenging. Herein, we report an efficient and stable catalyst comprising a Co single atom incorporated in an RuO 2 sphere for HER and OER, in which the Co single atom in the RuO 2 sphere was confirmed by XAS, AC-STEM, and DFT. This tailoring strategy uses a Co single atom to modify the electronic structures of the surrounding Ru atoms and thereby remarkably elevates the electrocatalytic activities. The catalyst requires ultralow overpotentials, 45 mV for HER and 200 mV for OER, to deliver a current density of 10 mA cm À 2 . The theoretical calculations reveal that the energy barriers for HER and OER are lowered after incorporation of a cobalt single atom.

The proposed working mechanism of the electrochemical CO2 reduction reaction on Fe1N4, Fe1N4–N1, and Fe1N4–O1 active sites.

We report a family of cationic lead halide layered materials, formulated as [Pb X ] [ O C(CH) CO ] (X=F, Cl, Br), exhibiting pronounced broadband white-light emission in bulk form. These well-defined PbX-based structures achieve an external quantum efficiency as high as 11.8 %, which is comparable to the highest reported value (ca.9 %) for broadband phosphors based on layered organolead halide perovskites. More importantly, our cationic materials are ultrastable lead halide materials, which overcome the air/moisture-sensitivity problems of lead perovskites. In contrast to the perovskites and other bulk emitters, the white-light emission intensity of our materials remains undiminished after continuous UV irradiation for 30 days under atmospheric conditions (ca.60 % relative humidity). Our mechanistic studies confirm that the broadband emission is ascribed to short-range electron-phonon coupling in the strongly deformable lattice and generated self-trapped carriers.

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Solar-driven photocatalytic reactions can mildly activate hydrocarbon C–H bonds to produce value-added chemicals. However, the inefficient utilization of photogenerated carriers hinders the application. Here, we report reversible photochromic BiOBr (denoted as p-BiOBr) nanosheets that were colored by trapping photogenerated holes upon visible light irradiation and bleached by water oxidation to generate hydroxyl radicals, demonstrating enhanced carrier separation and water oxidation. The photocatalytic coupling and oxidation reactions of ethylbenzene were efficiently realized by p-BiOBr in a water-based medium under ambient temperature and pressure (apparent quantum yield is 14 times that of pristine BiOBr). The p-BiOBr nanosheets feature lattice disordered defects on the surface, providing rich uncoordinated catalytic sites and inducing structural distortions and lattice strain, which further leads to an altered band structure and significantly enhanced photocatalytic performances. These hole-trapping materials open up the possibility of substantially elevating the utilization efficiency of photogenerated holes for high-efficiency photocatalytic activation of various saturated C–H bonds.