Si Single-Atom Sites Anchored Carbon Anode Achieving the Zero-Strain Feature and Superior Li+ Storage Performance.

Overcoming the significant volume strain in silicon-based anodes has been the focus of research for decades. The strain/stress in silicon-based anodes is inversely proportional to their size. In this study, we design atomic Si sites to achieve the ultimate size effect, which indeed exhibits a zero-strain feature. Compared with conventional silicon-based anodes with alloying addition reactions, the lithium-ion storage mechanism of atomic Si sites is solid-solution reactions, which brings about the zero-strain feature. Additionally, the ligand structure of atomic Si sites remains constant during cycling. This zero-strain feature results in excellent cycling stability. Furthermore, the exposed atomic Si sites enhance the electrochemical reaction kinetics, leading to outstanding rate performance. Moreover, the anode inherits the advantages of silicon-based anodes, including a low working voltage (~0.21 V) and high specific capacity (~2300 mAh g-1 or ~1203 mAh cm-3). This work establishes a novel pathway for designing low/zero-strain anodes.

Fast one-pot synthesis of a Se-rich MnCdSe solid solution for highly efficient cocatalyst-free photocatalytic H2 evolution.

Designing high-efficiency and stable metal selenides for visible-light-induced photocatalytic H2 production has been challenging. Here, a novel class of Se-rich MnCdSe solid solution with a tunable band structure is fabricated through a fast one-pot strategy. In the absence of any cocatalysts, the optimal MnCdSe nanocrystals exhibit a much higher visible-light-driven H2 evolution activity (2582 µmol g-1 h-1) than the pristine CdSe (30 µmol g-1 h-1), and achieve an apparent quantum yield (AQY) of 7.5% at 420 nm. This work opens a new gateway to explore metal selenide-based solid solutions for photocatalytic applications.

Composition-dependent activity of ZnxCd1-xSe solid solution coupled with Ni2P nanosheets for visible-light-driven photocatalytic H2 generation.

Metal selenide semiconductors have been rarely used for photocatalytic water splitting because of their poor stability and severe photocorrosion properties. Hence, designing stable metal selenides with suitable bandgap energies has considerable practical significance in photocatalytic H2 evolution. In this work, a novel series of ZnxCd1-xSe (x = 0 âˆ¼ 1) with tunable band structure were fabricated through a simple solvothermal method. Impressively, the ZnSe exhibited a maximum H2 production rate of 1056 µmol g-1h-1, which was higher than that of CdSe and ZnxCd1-xSe solid solutions. Such visible-light photoactivity for water reduction to H2 was attained even after 6 cycling photocatalytic experiments. Moreover, the two-dimensional (2D) Ni2P nanosheets act as a high-efficiency cocatalyst integrated with ZnxCd1-xSe semiconductor to boost photocatalytic H2 generation performance. The optimal 8% Ni2P/ZnSe composites displayed excellent cycling stability and superior photocatalytic H2 evolution performance (4336 µmol g-1h-1), which was about 4.1 times that of pure ZnSe under visible light irradiation. Photoelectrochemical (PEC), photoluminescence (PL), and time-resolved photoluminescence (TRPL) measurements reveal that the improved photoactivity Ni2P/ZnSe photocatalysts were ascribed to the effective separation and migration of photoinduced carriers. The present work paves a pathway to explore the fabrication of ZnxCd1-xSe solid solutions and the hybridization of 2D transition metal phosphides nanosheets toward photocatalytic applications.