S-Scheme and Schottky Junction Synchronous Regulation Boost Hierarchical CdS@Nb₂O₅/Nb₂CT_x (MXene) Heterojunction for Photocatalytic H₂ Production

Abstract

Photocatalytic water cracking hydrogen (H2) production is a promising clean energy production technology. Therefore, a ternary CdS@Nb2O5/Nb2CT x (MXene) heterojunction with hierarchical structure was designed to promote photocatalytic H2 evolution. When Na2S/Na2SO3 and lactic acid were used as sacrificial agents, the hydrogen evolution reaction (HER) rates of the optimized photocatalyst were 1501.7 and 2715.8 μmol g–1 h–1, with 12.4% and 26.1% apparent quantum efficiencies (AQE) at 420 nm, respectively. Its HER performance was 10.9-fold higher than that of pure CdS and remained 87% activity after five rounds of cycle tests. Such an enhancement stems from the excellent light absorption properties, tight interfacial contact, fast charge transfer channel, and sufficient active sites. Mechanism analysis demonstrates that S-scheme and Schottky junction synchronous regulation boost hierarchical CdS@Nb2O5/Nb2CT x for photocatalytic H2 production. This work creates possibilities for manufacturing Nb-based MXene photocatalysts for converting solar energy and other applications.

Efficient NADH Regeneration without Electron Mediator toward Enzymatic CO2 Reduction Enabled by a Lawn-like TP-COFs/Ti3C2Tx (MXene) Photocatalyst

“…These results indicate that TCM-15% possesses the capability to regenerate NADH. ,,, Additionally, the VB of TCM-15% (1.13 V) is more positive than the oxidation potential of TEOA (1.07 V), suggesting that TCM-15% enables the oxidation of TEOA . In this situation, the TCM with lawn-like microstructure is conducive to the electron transfer and separation from the photoexcited center TP-COFs to the highly conductive Ti 3 C 2 T x MXene, which enables the promotion of the recycling and regeneration of NAD + to NADH. , …”

In Situ Self-Oxidation of Few-Layered Nb2CTx Nanosheets in Aqueous Solution for Achieving Improved Humidity Sensitivity and Selectivity

“…FTIR was further performed to check the surface chemical constituents of the three samples. As shown in Figure (g), these are most likely vibrations located at 597.8 cm –1 (Nb–O), 1062.5 cm –1 (C–O), 1221.2 cm –1 (C–F), 1309.9 cm –1 , 1404.8 cm –1 (C–H), 1523.0 cm –1 , 1593.3 cm –1 (CC), 1692.7 cm –1 (CO), 2851.7 cm –1 , 2938.9 cm –1 (C–H), and 3301.5 cm –1 (O–H) for the as-prepared few-layered Nb 2 CT x nanosheets. − With the increase of incubation duration, most of the vibrational modes of the bonds are eradicated, while the Nb–O and CC bonds are preserved and even enhanced for few-layered Nb 2 CT x nanosheets after 17 and 37 days incubation. The FTIR results exhibit similarity to those obtained from XPS and Raman spectroscopy.…”

Applications of BiOX in the Photocatalytic Reactions

“…Photocatalytic splitting of H 2 O began in 1972, when Fujishima and Honda discovered that H 2 O molecules could be split at a titanium dioxide electrode to produce hydrogen and oxygen under the photocatalysis, making it possible to use solar energy to split H 2 O into hydrogen [49]. After decades of exploration, many related photocatalysts have been discovered, such as TiO 2 , ZnO, CdS, ZnS, GaN, and so on [50][51][52][53][54]. In recent years, BiOX photocatalysts have also been applied to split H 2 O to produce hydrogen and oxygen gas, and some excellent results have been achieved [36,[55][56][57][58][59][60].…”

“…The kinetic realization of the BiOX photocatalytic splitting of H 2 O for hydrogen and oxygen production requires the following four processes (Figure 1 into hydrogen [49]. After decades of exploration, many related photocatalysts have been discovered, such as TiO2, ZnO, CdS, ZnS, GaN, and so on [50][51][52][53][54]. In recent years, BiOX photocatalysts have also been applied to split H2O to produce hydrogen and oxygen gas, and some excellent results have been achieved [36,[55][56][57][58][59][60].…”