the emerging global energy crisis. [1] To boost the hydrogen production efficiency, the rational design and fabrication of semiconductor photoelectrodes with broad light absorption, adequate exciton generation, efficient charge separation/transfer, and long-term stability are highly desired. [2] Recently, semiconductors quantum dots (QDs) have demonstrated huge potential as light sensitizers in photoanodes for high efficiency solar-driven PEC application due to their size/shape/composition-tunable optical properties that features considerable overlap with solar spectrum. [3] However, the state-of-the-art QDs used in current PEC systems still suffer from major limitations including highly toxic heavy metal elements (Pb, Cd etc.), insufficient charge separation/transfer, and low photo-stability. [1b,4] Developing eco-friendly core/shell structured QDs is a promising strategy to address these issues, while a proper selection of core and shell materials is necessary to obtain core/shell QDs with tailored band structure, optimized optical properties/ charge dynamics, and enhanced photo/chemical stability for high performance and stable solar-to-hydrogen conversion.Among various semiconductor QDs, heavy metal-free InP QDs have recently attracted great attention due to their large absorption coefficient, narrow band gap (≈1.34 eV in bulk), and wide wavelength tunability. [5] Nevertheless, bare InP QDs can exhibit abundant surface defect states, resulting in severe non-radiative recombination for largely reduced quantum yield (QY, usually <5%) and photo/chemical stability. [6] Generally, inorganic shell (such as ZnS and ZnSe) were coated on InP core QDs to form type I band alignment with improved radiative emission and photo/chemical stability. [7] Considering the stress-induced defects at the core/shell interface, the ZnSe shell with a lower lattice mismatch (3.4%) as compared to ZnS (7.6%) is more appropriate to coat on InP core for optimized optical characteristics. [8] In 2019, Jang et al. synthesized InP/ZnSe/ZnS QDs to fabricate a red QDs-light-emitting diode (QLED) with an external quantum efficiency of 21.4%, which is considered as a milestone for the display application based on environmentally friendly QDs, demonstrating the huge potential of InP-based core/shell QDs as building blocks in optoelectronic devices. [9] However, to date, most of the investigations regarding InP-based core-shell QDs are mainly focused on enhancing As emerging eco-friendly alternatives to traditional Cd/Pb-based quantum dots (QDs), InP/ZnSe(S) core/shell QDs have demonstrated huge potential in light-emitting technologies. So far, these QDs have been rarely employed in solar energy conversion applications due to their type-I band structure offering limited photo-induced charge carrier separation and transfer. Here, a controllable Cu shell doping approach is reported to engineer the optoelectronic properties of InP/ZnSe core/shell QDs and realize high performance and stable solar-driven photoelectrochemical (PEC) hydrogen evol...

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Near-infrared-emitting CuGaS2/CdS QDs with enhanced visible light absorption were developed to achieve high efficiency photoelectrochemical cells.

A high performance photoelectrochemical cell fabricated using eco-friendly Mn-alloyed CuInS2/ZnS core/shell quantum dots is demonstrated.

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To develop highly efficient electrochemical catalysts for N 2 fixation is important to sustainable ambient NH 3 production through the N 2 reduction reaction (NRR). Herein, we demonstrate the development of vanadium phosphide nanoparticle on V foil as a highefficiency and stable catalyst for ambient NH 3 production with excellent selectivity. The high Faradaic efficiency of 22% with a large NH 3 yield of 8.35 × 10 −11 mol•s −1 •cm −2 was obtained at 0 V vs. the reversible hydrogen electrode in acid solution, superior to all previously studied V-based NRR catalysts. Density functional theory calculations are also utilized to have an insight into the catalytic mechanism.

Low‐cost and high‐performance photoelectrochemical (PEC) hydrogen production based on eco‐friendly colloidal core/shell quantum dots (QDs) represents a newly developing solar technology toward carbon neutrality. Herein, we present the synthesis of a novel type of environment‐friendly CuGaS2 (CGS)/ZnSe core/shell QDs with shell thicknesses‐tunable optoelectronic properties. As compared to CGS bare QDs, the prepared CGS/ZnSe core/shell QDs show enhanced visible light absorbance, emerging photoluminescence emission, tunable exciton lifetime, and improved photo‐stability. As a proof‐of‐concept, these eco‐friendly CGS/ZnSe core/shell QDs were applied as light sensitizers in a solar‐driven PEC hydrogen production system, delivering a nearly six times higher photocurrent density and improved device durability with respect to that of CGS core QDs under standard one sun AM 1.5G illumination. Our findings imply that such eco‐friendly core/shell QDs with tailored optoelectronic properties hold great potential for future “green” QDs‐based solar energy technologies.

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