An Unprecedented Strategy to Fabricate Inside/Surface Homojunction in Bismuth Oxychloride for Efficient Photocatalysis

Abstract

The design of an efficient homojunction in bismuth oxychloride via simple means is still challenging. Herein, an inside/ surface homojunction of bismuth oxychloride via fabricating surface-layer oxygen vacancies from a sulfur dopant and surfacelayer hydroxyl from an alkali modification (BOCSO) in a one-pot hydrothermal process is successfully prepared. BOCSO exhibits enlarged specific surface area, improved adsorption of substrate, and enhanced photogenerated charge separation and transfer efficiencies. Extensive characterizations and density functional theory (DFT) calculations demonstrate BOCSO can form a defect level via surface oxygen vacancies and S doping to narrow the energy gap and capture the photogenerated electrons and holes. Meanwhile, both oxygen vacancies and hydroxyls on the BOCSO surface can also form an inside/surface homojunction containing an interfacial electric field (IEF) to induce a direct Z-scheme charge transfer mechanism. Taking advantage of the above, the photocatalytic degradation activity is remarkably elevated compared to that of pristine BiOCl (BOC). This work provides a new strategy for the fabrication of an inside/surface homojunction in bismuth oxychloride via novel surface modification engineering.

Co-assembled MoS2–TiO2 Inverse Opal Photocatalysts for Visible Light-Activated Pharmaceutical Photodegradation

“…40 On the other hand, the presence of 0.3 MoS 2 -PC425 films resulted in markedly enhanced VLA reduction of TC and CIP concentrations reaching degradation levels, defined as (1 − C/ C 0 ) × 100% of 56% (Figure 6b) and 23% (Figure 6e), respectively, after 60 min of visible light illumination. Both TC and CIP photodegradation kinetics followed pseudo-first-order kinetics (Figure 6c,f), with apparent kinetic constants k of 0.0119 and 0.00351 min −1 , respectively, which are comparable to those reported for TC and CIP photodegradation by MoS 2 −TiO 2 43,63 as well as other heterostructured photocatalysts involving MoS 2 and Bi-based and carbon nitride VLA semiconductors in the form of powders (Table S3). The photocatalytic stability of the 0.3 MoS 2 -PC425 films was assessed after four successive TC degradation experiments under visible light using the same film, where a small decrease in photocatalytic activity (the kinetic constants k decreased by ca.…”

“…In this work, heterostructured MoS 2 –TiO 2 inverse opal films are demonstrated as efficient immobilized VLA photocatalysts for the degradation of pharmaceutical emerging contaminants, including two representative broad-spectrum antibiotics, tetracycline (TC) and ciprofloxacin (CIP), whose photocatalytic removal is attracting increasing attention toward water remediation. – The challenging integration of MoS 2 in three-dimensional (3D) TiO 2 PC films was undertaken via the co-assembly method, enabling the in situ incorporation of MoS 2 nanosheets to the TiO 2 inverse opal skeleton by a straightforward one-pot approach beyond conventional top-down (impregnation and spin/dip-coating) and bottom-up (chemical vapor, chemical bath, and hydrothermal) deposition methods. Structure–activity relations were explored for the MoS 2 –TiO 2 PC films with respect to compositional and structural optimization as well as PBG engineering by varying the nanosheet loading and colloidal template diameter together with performance screening on the VLA photocatalytic degradation of salicylic acid (SA), a persistent metabolite of acetylsalicylic acid that is commonly detected in wastewaters .…”

Boosting Visible-Light Photocatalytic Activity of BiOCl Nanosheets via Synergetic Effect of Oxygen Vacancy Engineering and Graphene Quantum Dots-Sensitization

“…The intensity of 2 wt% GQDs/BiOCl-V O was higher than that of BiOCl. These results indicate that ·O 2 − radicals are formed by electron reduction [ 44 , 45 ]. As seen in Figure 6 (Cc1–Cc4), DMPO–·OH displayed four peaks with an intensity ratio of 1:2:2:1.…”

Metal-doped carbon nitride: an all-in-one photocatalyst

“…After the reaction, the sample still maintained the crystal structure, which further demonstrated the recyclability of the sample. 142 The stability of the performance and the stability of the structure are mutually restricted, which determines the stability of the material. The good stability enables the catalyst to continue to maintain its high efficiency in the long-running process.…”