Self‐powered photodetectors are considered as a new type of photodetectors enabling self‐powered photodetection without external power. The excellent photoresponsivity, fast photoresponse rate, low dark current, and large light on/off ratio of these photodetectors have attracted wide interest among scholars. 2D materials are widely used in self‐powered photodetectors due to their excellent optical and electrical properties, unique 2D structures, and their capabilities to exhibit excellent photodetection performance. According to the self‐driving mechanism of 2D material‐based self‐powered photodetectors, they are divided into three categories: p–n junction photodetectors, Schottky junction photodetectors, and photoelectrochemical photodetectors. From these three perspectives, the research progress of 2D material‐based self‐powered photodetectors is summarized in detail here. Research reports indicate that 2D material‐based self‐powered photodetectors have excellent self‐powered photoresponse behavior, good light on/off characteristics, and wideband spectral response ranges. The excellent photoresponse performance of 2D material‐based self‐powered photodetectors facilitates their potential applications in the field of optoelectronic devices. In particular, self‐powered photodetectors have great potential as novel emerging self‐driven optoelectronic devices. Finally, directions for the further development of 2D material‐based self‐powered photodetectors are anticipated.

Large-size 2D black phosphorus (BP) nanosheets have been successfully synthesized by a facile liquid exfoliation method. The as-prepared BP nanosheets are used to fabricate electrodes for a self-powered photodetector and exhibit preferable photoresponse activity as well as environmental robustness. Photoelectrochemical (PEC) tests demonstrate that the current density of BP nanosheets can reach up to 265 nA cm −2 under light irradiation, while the dark current densities fluctuate near 1 nA cm −2 in 0.1 M KOH. UV-vis and Raman spectra are carried out and confirm the inherent optical and physical properties of BP nanosheets. In addition, the cycle stability measurement exhibits no detectable distinction after processing 50 and 100 cycles, while an excellent on/off behavior is still preserved even after one month. Furthermore, the PEC performance of BP nanosheets-based photodetector is evaluated in various KOH concentrations, which demonstrates that the as-prepared BP nanosheets may have a great potential application in self-powered photodetector. It is anticipated that the present work can provide fundamental acknowledgement of the performance of a PEC-type BP nanosheets-based photodetector, offering extendable availabilities for 2D BPbased heterostructures to construct high-performance PEC devices.

Black phosphorus (BP) is a new rediscovered layered material, which has attracted enormous interests in the field of electrocatalysis. Recent investigations reveal that bulk BP is a promising electrocatalyst for oxygen evolution reactions (OER), whereas its bulk crystal structure restricts sufficient active sites for achieving highly efficient OER catalytic performances. Toward this end, few‐layer BP nanosheets prepared by facile liquid exfoliation are applied as electrocatalysts and exhibit preferable electrocatalytic OER activity in association with structural robustness; subsequently, the dependence of current density and applied bias potential on the concentration of OH− has also been uncovered. Most importantly, we are aware that reduction in the thickness of BP nanosheets would generate extra active sites from the ultrathin planar structure and complimenting to the electrocatalytic activities. It is further anticipated that the current work might provide further implementation about the OER performance of BP nanosheets, thereby, offering extendable availabilities for BP‐based electrocatalysts in constructing high‐performance OER devices.

The band gap of few‐layered 2D material is one of the significant issues for the application of practical devices. Due to the outstanding electrical transport property and excellent photoresponse, 2D InSe has recently attracted rising attention. Herein, few‐layered InSe nanosheets with direct band gap are delivered by a facile liquid‐phase exfoliation approach. We have synthesized a photoelectrochemical (PEC)‐type few‐layered InSe photodetector that exhibits high photocurrent density, responsivity, and stable cycling ability in KOH solution under the irradiation of sunlight. The detective ability of such PEC InSe photodetector can be conveniently tuned by varying the concentration of KOH and applied potential suggesting that the present device can be a fitting candidate as an excellent photodetector. Moreover, extendable optimization of the photodetection performance on InSe nanosheets would further enhance the potential of the prepared InSe in other PEC‐type devices such as dye‐sensitized solar cells, water splitting systems, and solar tracking equipment.

Solar-to-fuel conversion through photocatalytic process is regarded as a promising technology with the potential to reduce the reliance on the dwindling reserved fossil fuels and to support the sustainable development...