Boosted Charge Transfer Efficacy of an All‐Solid‐State Z‐Scheme BiOI‐CD‐CdS Photocatalyst for Enhanced Degradation of 4‐Nitrophenol and Oxidation of Benzyl Alcohol under Visible Light**

Abstract

Recently, utilization of solar light for chemical reactions has become a popular approach. Inspired by nature, we fabricated a ternary system, BiOI-CD-CdS, which is more durable and shows multiple photocatalytic applications. The incorporated carbon dots (CD) serve as a solid-state electron mediator and Zscheme facilitator. The material was employed for photooxidative degradation of 4-nitrophenol (a pollutant) and selective oxidation of benzyl alcohol into the corresponding aldehyde in an acetonitrile medium. In this study, 10 wt % BiOI-CD-CdS (denoted as 10 wt % BCC) shows the highest photocatalytic performance compared to the individual semiconductors BiOI and CdS, and gave a degradation rate constant (k) of 12.67 × 10 À 3 min À 1 (4-nitrophenol), which is 17.5 times and 6.5 times higher than its individual components. Moreover, the catalyst offers a 90 % conversion of benzyl alcohol to benzaldehyde with high selectivity (98 %). Directed by mechanistic insight, the charge transfer process was observed between BiOI and CdS, where CD serves as an electron mediator/charge separator. The radicals formed by the photocatalysis are superoxide (O 2 * À ), hydroxyl radicals ( * OH), and holes (h + ). The intermediates and mechanistic pathways were traced using HPLC, GC-MS, and EPR studies. Moreover, the work demonstrated a smart strategy for designing a ternary Z-scheme photocatalytic system, which could be useful for environmental decontamination and selective organic transformation under visible light.

Enhanced photocatalytic activity of porous TiO2 containing C/P/K derived from grapefruit peel

“…It indicates that h + can be produced when exposed to light, and can react with TEMPO, therefore, the signal intensity of the TEMPO is weakened. 48,49 EPR tests confirm the production of ˙O 2 − , ˙OH, and h + radicals in the CPK-TiO 2 -10 photocatalytic degradation system for RhB.…”

“…It indicates that h + can be produced when exposed to light, and can react with TEMPO, therefore, the signal intensity of the TEMPO is weakened. 48,49 EPR tests conrm the production of cO 2…”

Visible‐Light Driven Z‐Scheme Water Splitting over NiS/CdS/PtOx/WO3 through Modulating Redox Mediator Environments

“…At present, it is still difficult to use metal sulfide as HEP for Z‐scheme. The Z‐scheme electron transfer has been realized in CdS/RGO/Fe 2 V 4 O 13 , [29] CdS/Ag/Bi 2 MoO 6 , [30] CdS/Au/ZnO, [31] CdS/Ag/TiO 2 , [32] Zn 0.5 Cd 0.5 S/RGO/g‐C 3 N 4 , [33] CdS/Ag/BiVO 4 , [34] BiOI‐CD‐CdS, [35] etc. Though, few have achieved OWS using their Z‐scheme electron transfer mode, such as CuGaS 2 /RGO/BiVO 4 [36] .…”