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Dye-sensitized system holds great potential for the development of visible-light-responsive photocatalysts not only because it can enhance the light absorption and charge separation efficiency of the systems but also because it can tune the band structure of catalysts. Herein, two-dimensional (2D) Fe-MOF nanosheets (Fe-MNS) with a LUMO potential of 0.11 V (vs. RHE) was prepared. Interestingly, it has been found that when the 2D Fe-MNS catalyst was functionalized with visible-light-responsive [Ru(bpy)]32+ as a dye-sensitizer, the electrons from the [Ru(bpy)]32+ can effectively inject into the 2D Fe-MNS, which resulted in a negative shift of the LUMO potential of the 2D Fe-MNS to −0.15 V (vs. RHE). Consequently, the [Ru(bpy)]32+/Fe-MNS catalytic system exhibits a sound photocatalytic CO2-to-CO activity of 1120 μmol g-1h−1 under visible-light-irradiation. The photocatalytic CO production was further ameliorated by regulating the electronic structure of the 2D Fe-MNS by doping Co ions, achieving a remarkable photocatalytic activity of 1637 μmol g-1h−1. This work further supports that the dye-sensitized system is an auspicious strategy worth exploring with different catalysts for the development of visible-light-responsive photocatalytic systems.

Photoreduction of CO2 to valuable fuels with semiconductor photocatalysts is a good solution to the problems of global warming and energy crisis. Creation of hybrid nanomaterials with hierarchical and/or heterojunction structures is beneficial to develop efficient photocatalysts for CO2 reduction. Herein we present a convenient method to obtain a hybrid photocatalyst consisting of MnS and In2S3 nanosheets with assembled hierarchical structures through using Mn2+-loaded MIL-68(In) submicro-rods as templates. Owing to the dispersive Mn2+ and In3+ ions in templates, numerous small p-n heterojunctions of MnS/In2S3 could be simultaneously produced in each hierarchical particle. The p-type MnS and n-type In2S3 with an original type II band alignment can create a stronger built-in electric field after the formation of p-n heterojunctions, which is favorable for charge separation and migration to catalyst surface. The prepared MnS/In2S3 heterojunctions show an 4-fold higher photocatalytic activity toward CO2 reduction than pristine MnS and In2S3. The MnS/In2S3 hierarchical structures were well characterized and their working mechanism was explored. This work demonstrates a facile strategy to create efficient hybrid photocatalysts with both hierarchical structures and p-n heterojunctions for photocatalytic applications.

All-inorganic lead-free halide double perovskites have emerged as rising star photocatalysts to substitute the toxic lead-based hailed perovskites (LHPs) owing to their unique photophysical properties. Nevertheless, their photocatalytic activities toward CO

Developing near-infrared responsive (NIR) photocatalysts is very important for the development of solar-driven photocatalytic systems. Metal sulfide semiconductors have been extensively used as visible-light responsive photocatalysts for photocatalytic applications owing to their high chemical variety, narrow bandgap and suitable redox potentials, particularly the benchmark ZnIn

Dye-sensitized system holds great potential for the development of visible-light-responsive photocatalysts not only because it can enhance the light absorption and charge separation efficiency of the systems but also because it can tune the band structure of catalysts. Herein, two-dimensional (2D) Fe-MOF nanosheets (Fe-MNS) with a LUMO potential of 0.11 V (vs. RHE) was prepared. Interestingly, it has been found that when the 2D Fe-MNS catalyst was functionalized with visible-light-responsive [Ru(bpy)]

Splitting water into hydrogen (H2) with sunlight is an appealing approach towards alleviating the fossil fuel crisis. However, as one of the most promising light harvesters, colloidal quantum dots (QDs) generally exhibit low photocatalytic activity towards H2 evolution because of the lack of catalytic sites on their surface. Many researchers have focused on activating QDs by anchoring metal complexes on their surface, in which the photoexcited electrons may transfer from the QDs to the metal centres via the organic ligands. These bulky organic ligands usually have poor electrical conductivity and chemical instability, thereby causing high charge recombination and low durability in these QDs/metal complex catalysts. To address these issues, we herein report the doping of cadmium telluride (CdTe) QDs with nickel ions (Ni2+), achieving a remarkable H2 generation rate without the use of co-catalysts. The formation rate of H2 exceeded 27.3 mmol/g/h under visible light irradiation, which is approximately 110-fold higher than that of pristine CdTe QDs. This doping strategy provides a versatile route to reduce protons to H2 with a turnover number of 13,650 in terms of Ni and confer superior durability on the CdTe QDs.

Photoreduction of CO

Converting CO2 into high-valued chemicals with sunlight is regarded as a promising way to solve the impending energy and environmental crisis. Development of efficient photocatalysts with suitable energy band gap, high stability and favorable structure is thus of very importance. Herein, a novel hierarchical Bi2WO6 photocatalyst assembled by Bi2WO6 nanosheets with a hollow and rod-shaped appearance has been developed via a facile hydrothermal process. Interestingly, we found that the hydrolysis of Bi(NO3)3 in water can produce solid Bi6O5(OH)3(NO3)5·3H2O microrods which can be transformed to hollow-hierarchical Bi2WO6 nanosheets by virtue of the Kirkendall effect. The developed Bi2WO6 nanosheets exhibit a 58 times higher specific surface area than that of bulk Bi2WO6 and a remarkable enhancement in electrochemical performance such as photocurrent and charge transfer. As a result, the hollow-hierarchical structured Bi2WO6 photocatalysts achieve a high CH4 yield of 2.6 μmol g−1 h−1, 8 times higher than that of bulk Bi2WO6. Moreover, the developed photocatalysts exhibit a high stability during the recycling experiments. This work may present a new strategy to attain hierarchical structured photocatalysts with high activity and stability toward CO2 reduction.

Photocatalytic degradation of environmental pollutants by using semiconductor-based photocatalysts offers great potential for remediation of toxic chemicals. For an economical and eco-friendly method to eliminate hexavalent chromium (Cr(VI)), favourable catalysts own high efficiency, stability and capability of harvesting light. Combination of metal with semiconductor is a promising route to improve the photocatalytic performance for Cr(VI) reduction. Herein, well-dispersed platinum (Pt) nanocubes (NCs) were synthesized by a facile one-step hydrothermal method with poly- l -lysine (PLL) as the growth-directing agent, followed by their uniform dispersion on graphitic carbon nitride (g-C3N4). Their morphology, crystal structure, chemical composition, and formation mechanism were mainly characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The hybrid nanocomposite was further explored for photocatalytic reduction of Cr(VI) to trivalent chromium (Cr(III)) under visible light at room temperature, by using formic acid (HCOOH) as a reducing agent, showing great improvement in photocatalytic activity and reusability, outperforming the referenced g-C3N4 and home-made Pt black/g-C3N4 catalysts. The effects of various experimental parameters and the proposed mechanism are discussed in detail.

Converting CO