Controlling autonomous propulsion of microswimmers is essential for targeted drug delivery and applications of micro/nanomachines in environmental remediation and beyond. Herein, we report two-dimensional (2D) carbon nitride-based Janus particles as highly efficient, light-driven microswimmers in aqueous media. Due to the superior photocatalytic properties of poly(heptazine imide) (PHI), the microswimmers are activated by both visible and ultraviolet (UV) light in conjunction with different capping materials (Au, Pt, and SiO₂) and fuels (H₂O₂ and alcohols). Assisted by photoelectrochemical analysis of the PHI surface photoreactions, we elucidate the dominantly diffusiophoretic propulsion mechanism and establish the oxygen reduction reaction (ORR) as the major surface reaction in ambient conditions on metal-capped PHI and even with TiO₂-based systems, rather than the hydrogen evolution reaction (HER), which is generally invoked as the source of propulsion under ambient conditions with alcohols as fuels. Making use of the intrinsic solar energy storage ability of PHI, we establish the concept of photocapacitive Janus microswimmers that can be charged by solar energy, thus enabling persistent light-induced propulsion even in the absence of illumination—a process we call “solar battery swimming”—lasting half an hour and possibly beyond. We anticipate that this propulsion scheme significantly extends the capabilities in targeted cargo/drug delivery, environmental remediation, and other potential applications of micro/nanomachines, where the use of versatile earth-abundant materials is a key prerequisite.

控制微游泳器的自主推进对于定向药物输送以及微/纳米机械在环境修复及其他领域的应用至关重要。在本文中，我们报道了基于二维（2D）氮化碳的Janus颗粒作为水性介质中高效的光驱动微游泳器。由于聚庚二酰亚胺（PHI）的优异光催化性能，微游泳者可通过可见光和紫外线（UV）以及不同的封盖材料（Au，Pt和SiO ₂）和燃料（H ₂ O ）来激活。₂和酒精）。通过对PHI表面光反应的光电化学分析的辅助，我们阐明了主要的扩散电泳推进机理，并建立了氧还原反应（ORR）作为环境条件下金属封端PHI甚至与TiO ₂的主要表面反应。基系统，而不是氢释放反应（HER），通常在以醇为燃料的环境条件下将其作为推进源。利用PHI的固有太阳能存储能力，我们建立了可以由太阳能充电的光电容Janus微游泳器的概念，从而即使在没有照明的情况下也能够持续产生光致推进力-我们称之为“太阳能电池游泳” ” —持续了半个小时，甚至可能超过了半个小时。我们预计，这种推进方案将显着扩展针对性的货物/药品交付，环境修复以及微型/纳米机械在其他潜在应用中的功能，在这些应用中，使用多种多样的地球富裕材料是关键前提。