Efficient 0D/2D Heterostructured Photocatalysts with Zn-AgIn₅S₈ Quantum Dots Embedded in Ultrathin NiS Nanosheets for Hydrogen Production

Abstract

Semiconductor quantum dots (QDs) have shown excellent advantages in photocatalysis owing to the unique optical properties, adjustable bandgap, and high specific surface area. However, the small size of QDs also brought severe charge recombination and particle agglomeration issues. Here, a simple QD-mediated precipitation method was used to create 0D/2D nanocomposites of Zn-AgIn 5 S 8 QDs anchored onto NiS nanosheets. The ultrathin Zn-AgIn 5 S 8 /NiS nanocomposites show obvious photocatalytic hydrogen production capacity due to the abundant active sites and efficient charge transportation in NiS nanosheets. With 7% of NiS, the maximized H 2 evolution rate reached 5.2 mmol g −1 h −1 , 11 times that of pure QDs. The apparent quantum efficiency of H 2 production achieves 14.9% at 420 nm at 5 °C. Interestingly, the maximum activity was achieved with 7% of NiS, higher than the normally used cocatalysts of 1−3%, which may be attributed to the ultrathin nature of the NiS nanosheets that simultaneously promoted the charge separation and catalytic activity but with minimized light-shielding effect. A reasonable mechanism of 0D/2D nanocomposite photocatalyst was proposed. This study supplies a simple QD-mediated precipitation method for the construction of ultrathin 0D/2D nanocomposites and also a novel strategy to improve the efficiency of sulfide photocatalysts.

Ag–In–Zn–S Quantum Dot-Dominated Interface Kinetics in Ag–In–Zn–S/NiFe LDH Composites toward Efficient Photoassisted Electrocatalytic Water Splitting

“…ZAIS QDs also have a strong light-harvesting capability, which was analyzed using UV–vis absorption and PL spectra in Figure c, indicating the outstanding performance of photoelectron generation. The UV–vis spectra indicate that pure ZAIS QDs have excellent light-absorption ability in the visible light region owing to the absorption onset up to 650 nm . Furthermore, the PL spectra of ZAIS QDs show an emission peak at 638 nm, which indicates that ZAIS QDs have a light response and the ability to generate electrons and holes under light irradiation that can be potentially used in P-EC .…”

Recent Progress in Quantum Dots Modified g‐C3N4‐based Composite Photocatalysts

“…The QDs modified g‐C 3 N 4 ‐based composite photocatalysts can effectively transfer charge and increase the rate of hydrogen production, and QDs can be used as photoelectric response sources for light excitation. In addition, g‐C 3 N 4 could also be modified by CdS QDs, [29] Ni 2 P QDs, [50] Zn‐AgIn 5 S 8 QDs [51] or Ag QDs [52] to form 2D/0D structure, and modified by Cd 0.5 Zn 0.5 S QDs [53] or MoS 2 QDs [54] to form 3D/0D structure. It also can be combined with SnO2‐ZnO QDs [55] to form 2D/0D/0D structure.…”

Double-Phase Heterostructure within Fe-Doped Cu2–xS Quantum Dots with Boosted Electrocatalytic Nitrogen Reduction

“…Ammonia (NH 3 ), as a key component in the chemical industry, not only exhibits a critical effect in the production of fertilizers, plastics, and textiles but also shows good potential as a hydrogen carrier. − Up to now, the industrial production of NH 3 is led by the traditional Haber–Bosch process, which heavily depends on the reaction of N 2 and fossil-fuel-derived H 2 on Fe-based catalysts under extreme conditions (15–30 MPa, 350–550 °C). − Recently, electrocatalytic nitrogen reduction reaction (NRR) has attracted more and more attention because it can be performed at room temperature and ambient pressure without hydrogen input and greenhouse gas emission. − Great progress has been made in NRR, for which various catalysts based on noble metals, − transitional metals, − and non-metal materials − have been widely evaluated. Among various NRR catalysts, transition-metal materials have been widely studied due to their low price and high earth abundancy. − However, the NRR performance of these cheap transition-metal electrocatalysts is relatively low and requires more research input.…”