：Construction of vertical heterostructures by stacking two-dimensional (2D) layered materials via chemical bonds can be an effective strategy to explore advanced solar-energyconversion systems. However, it remains a great challenge to fabricate such the heterostructures based on conversional oxide-based compounds, as they either do not possess a 2D layered structure or are not suitable for epitaxial growth due to large lattice mismatch. Here, we report a vertical heterostructure of bismuth oxyhalide semiconductors fabricated through a hetero-epitaxial anion exchange method. Monolayer Bi 2 WO 6 was epitaxially grown on the exposed surface of BiOI to inhibit photo-corrosion and introduce active sites. Theoretical and experimental results revealed that electrons generated under visible-light irradiation can directly transfer to surface coordinatively unsaturated Bi atoms, which contribute to the adsorption and activation of reactant molecules. As a result, the Bi 2 WO 6 /BiOI vertical heterostructures exhibit significantly enhanced visible-light-driven NO oxidation activity compared with BiOI and Bi 2 WO 6.

The separation of electron–hole pairs has a significant influence on the photocatalytic process on semiconductors. In this work, BiOCl nanosheets with oxygen vacancies (BiOCl-OVs) have been prepared by reconstructing small hydrophobic BiOCl nanosheets. The transient photoresponse and the electron spin resonance (ESR) results prove that the separation of the charge carriers can be promoted by the oxygen vacancies via trapping the photoexcited electrons. Because of the improved charge separation and wide absorption of the solar spectrum, more photogenerated charge carriers are produced, as confirmed by the photocurrent response and the ESR measurements of the reactive oxygen species •O2 – and •OH. Consequently, BiOCl-OVs present enhanced photocatalytic properties toward NO removal. Our study illustrates the importance of the construction of vacancies for improving photocatalytic performance.

Metal nanoparticles (NPs) are heavily involved in photocatalytic transformations to manipulate charge separation and storage, yet the catalytic role of metal NPs in tuning the selectivity of photoreactions is rarely addressed. Here, the photodehydrogenative coupling of primary amines is selected as the model reaction to probe the catalytic role of Pt and Pd NPs supported on graphitic carbon nitride (Pt/C 3 N 4 and Pd/C 3 N 4 ). When Pt/C 3 N 4 is employed as the photocatalyst, imine is produced via dehydrogenative homocoupling of primary amines owing to the weak adsorption of photogenerated imines and H atoms on Pt NPs. In comparison, Pd/C 3 N 4 promotes the consecutive hydrogenation of photogenerated imines into secondary amines due to a strong affinity of both imine and H atom for the surface of Pd NPs. This strategy is applicable for the synthesis of a series of imines and secondary amines with high yields.

The selective oxidation of primary alcohols to aldehydes by O2 instead of stoichiometric oxidants (for example, MnVII, CrVI, and OsIV) is an important but challenging process. Most heterogeneous catalytic systems (thermal and photocatalysis) require noble metals or harsh reaction conditions. Here we show that the Bi24O31Br10(OH)δ photocatalyst is very efficient in the selective oxidation of a series of aliphatic (carbon chain from C1 to C10) and aromatic alcohols to their corresponding aldehydes/ketones under visible‐light irradiation in air at room temperature, which would be challenging for conventional thermal and light‐driven processes. High quantum efficiencies (71 % and 55 % under 410 and 450 nm irradiation) are reached in a representative reaction, the oxidation of isopropanol. We propose that the outstanding performance of the Bi24O31Br10(OH)δ photocatalyst is associated with basic surface sites and active lattice oxygen that boost the dehydrogenation step in the photo‐oxidation of alcohols.

solar-energy conversion process, not only in solar cell but also in photocatalysis, involves solar-light harvesting and photoexcited charge carrier separation/transportation. [8,9] Heterostructure, in which materials with different properties are integrated together, generally can harvest wide solar light derived from multi ple components and possesses prominent photoexcited charge separation/transportation properties benefiting from internal electric field formed at the heterointerface. [10] Hence, exploring suitable components to construct heterostructure represents an efficient and facile strategy to improve the solar energy conversion efficiency. Nowadays, 2D materials have attracted enormous research interest in optical electronic devices, catalysis, and solar-energy conversion fields due to their high specific surface area, [11] large fraction of surface exposed atoms, [12] and excellent mechanical, optical, and electronic properties. [13,14] Benefiting from layered structural properties, 2D materials are prone to be constructed into heterostructures. Typically, 2D heterostructures include vertical heterostructures in which the layers of various 2D materials are stacked vertically, [15] and lateral heterostructures in which multiple 2D materials are seamlessly stitched lateral. [16] Most of the current reported 2D heterostructures

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