Photoelectrochemical water splitting using semiconductor materials is one of the most promising methods for converting solar energy into chemical energy. Among the commonly used semiconductors, p-type CuBi₂O₄ is considered one of the most suitable photocathode materials and can allow a theoretical photocurrent density of about 20 mA·cm⁻² for photoelectrochemical water splitting. However, due to severe charge carrier recombination, the obtained photocurrent density is much lower than the theoretical value. Highly efficient photoelectrochemical performance relies on fast charge carrier separation and transport, and prompt reaction kinetics. In this study, we report the development of a polyoxometalate-modified CuBi₂O₄/Mg-CuBi₂O₄ homojunction photocathode to improve both the bulk and interfacial charge carrier transport in the photocathode. For the bulk of the photocathode, the built-in electric field originating from the CuBi₂O₄/Mg-CuBi₂O₄ homojunction promotes the migration of photo-excited electrons on the conduction band from pure CuBi₂O₄ to Mg-doped CuBi₂O₄. Additionally, the electric field facilitates the transfer of holes from the valence band of Mg-doped CuBi₂O₄ to pure CuBi₂O₄. This directional transfer of both photo-excited electrons and holes plays a significant role in promoting separation and suppressing the recombination of the charge carriers. On the surface of the photocathode, the reduced polyoxometalate co-catalyst Ag₆[P₂W₁₈O₆₂] (AgP₂W₁₈) was used as a proton sponge to accelerate surface reaction kinetics and suppress carrier recombination. These synergistic effects improved the photo-generated charge carrier transfer and reaction kinetics. As a result, the novel photocathode displayed excellent photoelectrochemical properties, and the photocurrent density was observed to be −0.64 mA·cm⁻² at 0.3 V vs. RHE, which is better than that of −0.39 mA·cm⁻² for a pure photocathode. Furthermore, the novel photocathode had an applied bias photon-to-current efficiency (ABPE) higher than 0.19% at 0.3 V vs. RHE. In contrast, the pure photocathode had an ABPE of ~0.12% under the same conditions. Additionally, when H₂O₂ was used as an electron scavenger, the photocurrent density was −3 mA·cm⁻² at 0.3 V vs. RHE, which is an improvement of approximately 1.5 times compared to the pure photocathode. Furthermore, the charge separation and charge injection efficiency of the novel photocathode were significantly improved compared with the pure photocathode. The experimental results conclusively indicate that the formation of the CuBi₂O₄/Mg-CuBi₂O₄ homojunction and AgP₂W₁₈ modification played a significant role in the improved performance of the CuBi₂O₄ photocathode. The performance of the novel photocathode was comparable with the results reported in previous studies, demonstrating its promising potential in real applications.

左旋肉碱，细胞城的“能量使者”，负责将长链脂肪酸送入线粒体进行β-氧化，释放能量。本文拟人化地描绘了其生物合成、组织分布、运输机制及在脂肪酸代谢中的关键作用，强调其在促进减肥和健康改善中的重要性，旨在普及左旋肉碱的科学知识，提升公众对其重要性的认识。

电磁污染问题的日益严重，亟需开发兼具高效吸波与热管理功能的多功能材料。本研究报道了一种基于界面工程化Mo₂C MXenes的双功能设计。通过熔盐刻蚀策略，金属离子(Cu/Fe)被原位掺杂到Mo₂C中，构建的异质结构显著增强了界面极化与缺陷诱导偶极弛豫。优化后的Mo₂C/Fe复合材料展现出卓越的吸波性能，在2.0 mm厚度下实现−41.8 dB的反射损耗及5.12 GHz的宽频带吸收。这种增强效应归因于优化的阻抗匹配与多尺度极化损耗机制的协同作用。此外，所制备的Mo₂C/Fe气凝胶具有超低密度(0.0235 g cm⁻³)和优异隔热性能(80 ℃时ΔT < 20 ℃)，在中性环境中表现出卓越的耐腐蚀性。本工作为先进MXene基复合材料开发了一种可行的设计策略，展示了其在高效电磁吸收与有效热绝缘方面的双重功能。