Two-dimensional (2D) materials with excellent photocatalytic properties and unique piezoelectric response have attracted great attention. However, these characters are rare for traditional 2D structures. With an intrinsic electric field, the Janus 2D materials show great promise in photocatalytic and out-of-plane piezoelectric applications. Herein, we show that Janus In2X2X′ (X and X′ = S, Se, and Te) monolayers are desirable in the overall water splitting and piezoelectric devices. Comprehensive investigations reveal that the band gaps of these Janus monolayers are from 0.34 to 2.27 eV. With proper band edge positions, strong solar absorption, fast transfer and efficient separation of carriers, and high solar to hydrogen (STH) efficiencies (reaching 37.70%), eight members of them stand out. Besides, the electrons and holes have sufficient driving forces in the process of redox reaction. The piezoelectric response for in- and out-of-plane is superior for all monolayers. These compelling features make them suitable for photocatalysts, sensors, actuators, and energy conversion devices.

Recently, Janus two-dimensional (2D) materials have received considerable interest due to their intrinsic vertical dipole and hence have great potential in photocatalytic and piezoelectric applications. Here, a new series of...

Neuromorphic systems can parallelize the perception and computation of information, making it possible to break through the von Neumann bottleneck. Neuromorphic engineering has been developed over a long period of time based on Hebbian learning rules. The optoelectronic neuromorphic analog device combines the advantages of electricity and optics, and can simulate the biological visual system, which has a very strong development potential. Low‐dimensional materials play a very important role in the field of optoelectronic neuromorphic devices due to their flexible bandgap tuning mechanism and strong light‐matter coupling efficiency. This review introduces the basic synaptic plasticity of neuromorphic devices. According to the different number of terminals, two‐terminal neuromorphic memristors, three‐terminal neuromorphic transistors and artificial visual system are introduced from the aspects of the action mechanism and device structure. Finally, the development prospect of optoelectronic neuromorphic analog devices based on low‐dimensional materials is prospected.