The lack of highly efficient, durable, and cost-effective electrocatalysts for the hydrogen evolution reaction (HER) working at high current densities poses a significant challenge for the large-scale implementation of hydrogen production from renewable energy. Herein, amorphous molybdenum tungsten sulfide/nitrogen-doped reduced graphene oxide nanocomposites (a-MoWS x /N-RGO) are synthesized by plasma treatment for use as high-performance HER catalysts. By adjusting the plasma treatment duration and chemical composition, an optimal a-MoWS x /N-RGO catalyst is obtained, which exhibits a low overpotential of 348 mV at a current density of 1000 mA cm −2 and almost no decay after 24 h of working at this current density, outperforming commercial platinum/carbon (Pt/C) and previously reported heteroatom-doped MoS 2 -based catalysts. Based on density functional theory (DFT) calculations, it is found that with a reasonable tungsten doping level, the catalytic active site (2S 2− ) shows excellent catalytic performance working at high current densities because extra electrons preferentially fill at 2S 2− . The introduction of tungsten tends to lower the electronic structure energy, resulting in a closer-to-zero positive 𝚫G H * . Excessive tungsten introduction, however, can lead to structural damage and a worse HER performance under high current densities. The work provides a route towards rationally designing high-performance catalysts for the HER at industrial-level currents using earth-abundant elements.

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High-efficiency blue perovskite emitters with fast fluorescence radiation are not only crucial to achieving high-quality displays but also highly desired for optical wireless communications and quantum information technologies. Here, we demonstrate the preparation of blue-emitting Eu 3+ -, Sb 3+ -, and Ba 2+ -induced CsPbBr 3 nanoplatelets with narrow spectral widths. Among them, Sb 3+ -doped CsPbBr 3 NPLs can reach a photoluminescence quantum yield of 95%, with a very short fluorescence lifetime of 1.48 ns and greatly reduced ligand dosage. Through nuclear magnetic resonance analysis and density functional theory calculations, we find that the dopant−ligand interaction and dopant-induced growth energy barrier decide the growth kinetics of doped nanoplatelets. These mechanisms offer a fresh route to controlling the dimension of nanoscale perovskite emitters and benefit the development of fast-radiative perovskite emitters.

Colloidal CsPbX3 (X = Br, Cl, or I) perovskite nanocrystals (PNCs) have emerged as low-cost, high-performance light-emitting materials, whereas the toxicity of lead limits their applications. Europium halide perovskites offer promising alternatives to lead-based perovskites due to their narrow spectral width and high monochromaticity. Nonetheless, the photoluminescence quantum yields (PLQYs) of CsEuCl3 PNCs have been very low (∼2%). Herein, Ni2+-doped CsEuCl3 PNCs have been first reported, exhibiting bright blue emission centered at 430.6 ± 0.6 nm with a full width at half-maximum of 23.5 ± 0.3 nm and a PLQY of 19.7 ± 0.4%. To the best of our knowledge, this is the highest PLQY value reported for CsEuCl3 PNCs so far, an order of magnitude higher than in previous work. DFT calculations demonstrate that Ni2+ enhances PLQY by concurrently increasing the oscillator strength and removing Eu3+ which hinders the photorecombination process. B-site doping offers a promising approach to enhance the performance of lanthanide-based lead-free PNCs.