In nature, microorganisms could sense the intensity of the incident visible light and exhibit bidirectional (positive or negative) phototaxis. However, it is still challenging to achieve the similar biomimetic phototaxis for the artificial micro/nanomotor (MNM) counterparts with the size from a few nanometers to a few micrometers. In this work, we report a fuel-free carbon nitride (C₃N₄)/polypyrrole nanoparticle (PPyNP)-based smart MNM operating in water, whose behavior resembles that of the phototactic microorganism. The MNM moves toward the visible light source under low illumination and away from it under high irradiation, which relies on the competitive interplay between the light-induced self-diffusiophoresis and self-thermophoresis mechanisms concurrently integrated into the MNM. Interestingly, the competition between these two mechanisms leads to a collective bidirectional phototaxis of an ensemble of MNMs under uniform illuminations and a spinning schooling behavior under a nonuniform light, both of which can be finely controllable by visible light energy. Our results provide important insights into the design of the artificial counterpart of the phototactic microorganism with sophisticated motion behaviors for diverse applications.

在自然界中，微生物可以感知入射可见光的强度并表现出双向（正或负）趋光性。然而，对于尺寸从几纳米到几微米的人工微/纳米电机（MNM）对应物，实现类似的仿生趋光性仍然具有挑战性。在这项工作中，我们报告了一种无燃料的氮化碳（C ₃ N ₄)/基于聚吡咯纳米颗粒 (PPyNP) 的智能 MNM 在水中运行，其行为类似于趋光微生物。MNM 在低照度下向可见光源移动，在高照度下远离可见光源，这依赖于同时集成到 MNM 中的光诱导自扩散泳和自热泳机制之间的竞争相互作用。有趣的是，这两种机制之间的竞争导致了一组 MNM 在均匀照明下的集体双向趋光性和在非均匀光下的旋转学校行为，这两者都可以通过可见光能量进行精细控制。