Ultrathin Visible‐Light‐Driven Mo Incorporating In2O3–ZnIn2Se4 Z‐Scheme Nanosheet Photocatalysts

Abstract

Inspired by natural photosynthesis, the design of new Z‐scheme photocatalytic systems is very promising for boosting the photocatalytic performance of H 2 production and CO 2 reduction; however, until now, the direct synthesis of efficient Z‐scheme photocatalysts remains a grand challenge. Herein, it is demonstrated that an interesting Z‐scheme photocatalyst can be constructed by coupling In 2 O 3 and ZnIn 2 Se 4 semiconductors based on theoretical calculations. Experimentally, a class of ultrathin In 2 O 3–ZnIn 2 Se 4 (denoted as In 2 O 3–ZISe) spontaneous Z‐scheme nanosheet photocatalysts for greatly enhancing photocatalytic H 2 production is made. Furthermore, Mo atoms are incorporated in the Z‐scheme In 2 O 3–ZISe nanosheet photocatalyst by forming the MoSe bond, confirmed by X‐ray photoelectron spectroscopy, in which the formed MoSe 2 works as cocatalyst of the Z‐scheme photocatalyst. As a consequence, such a unique structure of In 2 O 3–ZISe–Mo makes it exhibit 21.7 and 232.6 times higher photocatalytic H 2 evolution activity than those of In 2 O 3–ZnIn 2 Se 4 and In 2 O 3 nanosheets, respectively. Moreover, In 2 O 3–ZISe–Mo is also very stable for photocatalytic H 2 production by showing almost no activity decay for 16 h test. Ultraviolet–visible diffuse reflectance spectra, photoluminescence spectroscopy, transient photocurrent spectra, and electrochemical impedance spectroscopy reveal that the enhanced photocatalytic performance of In 2 O 3–ZISe–Mo is mainly attributed to its widened photoresponse range and effective carrier separation because of its special structure.