Photodepositing CdS on the Active Cyano Groups Decorated g‐C₃N₄ in Z‐Scheme Manner Promotes Visible‐Light‐Driven Hydrogen Evolution

Abstract

g‐C3N4/CdS heterojunctions are potential photocatalysts for hydrogen production but their traditional type‐II configuration generally leads to weak oxidative and reductive activity. How to construct the novel Z‐scheme g‐C3N4/CdS counterparts to address this issue remains a great challenge in this field. In this work, a new direct Z‐scheme heterojunction of defective g‐C3N4/CdS is designed by introducing cyano groups (NC‐) as the active bridge sites. Experimental observations in combination with density functional theory (DFT) calculations reveal that the unique electron‐withdrawing feature of cyano groups in the defective g‐C3N4/CdS heterostructure can endow this photocatalyst with numerous advantageous properties including high light absorption ability, strong redox performance, satisfactory charge separation efficiency, and long lifetime of charge carriers. Consequently, the resultant photocatalytic system exhibits more active performance than CdS and g‐C3N4 under visible light and reaches an excellent hydrogen evolution rate of 1809.07 µmol h−1 g−1, which is 6.09 times higher than pristine g‐C3N4. Moreover, the defective g‐C3N4/CdS photocatalyst maintains good stability after 40 h continuous test. This work provides new insights into design and construction of Z‐scheme heterojunctions for regulating the visible‐light‐induced photocatalytic activity for H2 evolution.

Constructing Direct Z‐Scheme Heterostructure by Enwrapping ZnIn2S4 on CdS Hollow Cube for Efficient Photocatalytic H2 Generation

“…[9,10] Recently, CdS-based Z-scheme heterojunctions such as g-C 3 N 4 /CdS, TiO 2 /CdS, and CoS x /CdS have been constructed for achieving excellent H 2 generation performances. [11][12][13] To further pursue the ultimate photocatalytic activity, incorporating a semiconductor with more negative CB potential where electrons have much stronger reduction ability on CdS to form direct Z-scheme heterojunction is urgently. By virtue of the appropriate CB and VB potentials, outstanding optical properties, and easy-grow nature, ternary metal chalcogenide of ZnIn 2 S 4 is an attractive material to combine with CdS for achieving Z-scheme heterojunction.…”

Design of well-defined shell–core covalent organic frameworks/metal sulfide as an efficient Z-scheme heterojunction for photocatalytic water splitting

“… 1,2 It is highly required to construct photocatalysts with a visible light absorption range, strong redox ability, high charge-separation efficiency, and long-term stability. 3 Recently, various Z-scheme heterostructure photocatalysts, such as Bi-based, 4 TiO 2 -based, 5 and metal sulfide-based 6 ones, have attracted tremendous interest in H 2 production from water splitting. 7,8 However, the traditional inorganic Z-scheme heterojunctions consisting of two inorganic semiconductors are limited in many vital aspects, such as aligned band structures, interfacial contact area and transmission of substrates in the process of photocatalytic reactions, resulting in poor photocatalytic efficiency.…”

Fullerene–Graphene Acceptor Drives Ultrafast Carrier Dynamics for Sustainable CdS Photocatalytic Hydrogen Evolution

“…From the economic view, CdS-based noble-metal-free materials (e.g., CdS/g-C 3 N 4 , CdS/Co 2 P, and CdS/P-doped Ni 2 S) have attracted considerable attention in high-efficiency photocatalysis. [5] For example, the cost-effective Co 2 P/CdS photocatalyst exhibited a full-spectrum-driven solar-to-H 2 production, corresponding to a quantum efficiency of 2.26% at 700 nm. [5b] Besides, 2D…”