Molecular Heterogeneous Photocatalysts for Visible-Light-Driven CO Reduction.

Photoreduction of CO to high-value chemical fuels presents an effective strategy to reduce reliance on fossil fuels and mitigate climate change. The development of a photocatalyst characterized by superior activity, high selectivity, and good stability is a critical issue for PCR. Molecular heterogeneous photocatalytic systems integrate the advantages of both homogeneous and heterogeneous catalysts, creating a synergistic enhancement effect that increases photocatalytic performance.

Recent Advances of Photocatalytic CO Reduction Based on Hybrid Molecular Catalyst/Semiconductor Photocatalysts: A Review.

Molecular catalysts often exhibit superior activity and selectivity in the process of photocatalytic reduction of CO (PCR). However, the practical application of molecular catalysts is restricted by the unsatisfied charge separation, low stability, and recycling difficulty. Fortunately, constructing organic-inorganic hybrids of molecular catalysts and semiconductors can tackle the above problems, which can improve the efficiency of charge separation and keep beneficial active sites simultaneously.

A Review of Metal-Organic Frameworks Derived Hollow-Structured Photocatalysts: Synthesis and Applications.

Photocatalysis is a most important approach to addressing global energy shortages and environmental issues due to its environmentally friendly and sustainable properties. The key to realizing efficient photocatalysis relies on developing appropriate catalysts with high efficiency and chemical stability. Among various photocatalysts, Metal-organic frameworks (MOFs)-derived hollow-structured materials have drawn increased attention in photocatalysis based on advantages like more active sites, strong light absorption, efficient transfer of pho-induced charges, excellent stability, high electrical conductivity, and better biocompatibility.

Molecular Engineering of Porous Fe-N-C Catalyst with Sulfur Incorporation for Boosting CO Reduction and Zn-CO Battery.

Transition metal-nitrogen-carbon (M-N-C) catalysts have emerged as promising candidates for electrocatalytic CO reduction reaction (CORR) due to their uniform active sites and high atomic utilization rate. However, poor efficiency at low overpotentials and unclear reaction mechanisms limit the application of M-N-C catalysts. In this study, Fe-N-C catalysts are developed by incorporating S atoms onto ordered hierarchical porous carbon substrates with a molecular iron thiophenoporphyrin.

Ionic Liquid Modified Fe-Porphyrinic Metal-Organic Frameworks as Efficient and Selective Photocatalysts for CO Reduction.

Porphyrin-based metal-organic frameworks (MOFs) are ideal platforms for heterogeneous photocatalysts toward CO reduction. To further explore photocatalytic MOF systems, it is also necessary to consider their ability to fine-tune the microenvironments of the active sites, which affects their overall catalytic operation. Herein, a kind of ionic liquid (IL, here is 3-butyric acid-1-methyl imidazolium bromide, BAMeImBr) was anchored to iron-porphyrinic Zr-MOFs with different amounts to obtain IL@MOF-526 (MOF-526 = ZrO(OH)(FeTCBPP), FeTCBPP = iron 5,10,15,20-tetra[4-(4'-carboxyphenyl)phenyl]-porphyrin, = 100, 200, and 400).

Photocatalytic antibacterial agents based on inorganic semiconductor nanomaterials: a review.

Microbial contamination and antibiotic pollution have threatened public health and it is important to develop a rapid and safe sterilization strategy. Among various disinfection strategies, photocatalytic antibacterial methods have drawn increasing attention due to their efficient disinfection performances and environment-friendly properties. Although there are some reviews about bacterial disinfection, specific reviews on photocatalysis focused on inorganic semiconductor nanomaterials are rarely reported.

Efficient Visible-Light-Driven Carbon Dioxide Reduction using a Bioinspired Nickel Molecular Catalyst.

Inspired by natural enzymes, this study presents a nickel-based molecular catalyst, [Ni(NS)]Cl (NiNS, NS=2,11-dithia[3,3](2,6)pyridinophane), for the photochemical catalytic reduction of CO under visible light. The catalyst was synthesized and characterized using various techniques, including liquid chromatography-high resolution mass spectrometry (LC-HRMS), UV-Visible spectroscopy, and X-ray crystallography. The crystallographic analysis revealed a slightly distorted octahedral coordination geometry with a mononuclear Ni cation, two nitrogen atoms and two sulfur atoms.

Dual-Functional Photocatalysis for Cooperative Hydrogen Evolution and Benzylamine Oxidation Coupling over Sandwiched-Like Pd@TiO @ZnIn S Nanobox.

Photocatalytic hydrogen evolution (PHE) over semiconductor photocatalysts is usually constrained by the limited light-harvesting and separation of photogenerated electron-hole pairs. Most of the reported systems focusing on PHE are facilitated by consuming the photoinduced holes with organic sacrificial electron donors (SEDs). The introduction of the SEDs not only causes the environmental problem, but also increases the cost of the reaction.

Perovskite Quantum Dots Encapsulated in a Mesoporous Metal-Organic Framework as Synergistic Photocathode Materials.

Metal halide perovskite quantum dots, with high light-absorption coefficients and tunable electronic properties, have been widely studied as optoelectronic materials, but their applications in photocatalysis are hindered by their insufficient stability because of the oxidation and agglomeration under light, heat, and atmospheric conditions. To address this challenge, herein, we encapsulated CsPbBr nanocrystals into a stable iron-based metal-organic framework (MOF) with mesoporous cages (∼5.5 and 4.

Critical Aspects of Metal-Organic Framework-Based Materials for Solar-Driven CO Reduction into Valuable Fuels.

Photoreduction of CO into value-added fuels is one of the most promising strategies for tackling the energy crisis and mitigating the "greenhouse effect." Recently, metal-organic frameworks (MOFs) have been widely investigated in the field of CO photoreduction owing to their high CO uptake and adjustable functional groups. The fundamental factors and state-of-the-art advancements in MOFs for photocatalytic CO reduction are summarized from the critical perspectives of light absorption, carrier dynamics, adsorption/activation, and reaction on the surface of photocatalysts, which are the three main critical aspects for CO photoreduction and determine the overall photocatalytic efficiency.

Functionalization of Zirconium-Based Metal-Organic Layers with Tailored Pore Environments for Heterogeneous Catalysis.

Intriguing properties and functions are expected to implant into metal-organic layers (MOLs) to achieve tailored pore environments and multiple functionalities owing to the synergies among multiple components. Herein, we demonstrate a facile one-pot synthetic strategy to incorporate multiple functionalities into stable zirconium MOLs via secondary ligand pillaring. Through the combination of Zr -BTB (BTB=benzene-1,3,5-tribenzoate) layers and diverse secondary ligands (including ditopic and tetratopic linkers), 31 MOFs with multi-functionalities were systematically prepared.

Platinum- and CuO -Decorated TiO Photocatalyst for Oxidative Coupling of Methane to C Hydrocarbons in a Flow Reactor.

Oxidative coupling of methane (OCM) is considered one of the most promising catalytic technologies to upgrade methane. However, C products (C H /C H ) from conventional methane conversion have not been produced commercially owing to competition from overoxidation and carbon accumulation at high temperatures. Herein, we report the codeposition of Pt nanoparticles and CuO clusters on TiO (PC-50) and use of the resulting photocatalyst for OCM in a flow reactor operated at room temperature under atmospheric pressure for the first time.

Spatially Separated Bifunctional Cocatalysts Decorated on Hollow-Structured TiO for Enhanced Photocatalytic Hydrogen Generation.

Efficient charge separation can promote photocatalysis of semiconductors. Herein, a hollow-structured TiO sphere decorated with spatially separated bifunctional cocatalysts was designed, which exhibited enhanced photocatalytic hydrogen generation. Ultrasmall-sized MO (M = Pd, Co, Ni, or Cu) nanoparticles (NPs) were first introduced into a zeolite via confinement synthesis, and then, hollow TiO was fabricated by using the zeolite as a sacrificial template forming MO@TiO.

Visible-Light-Driven Conversion of CO to CH with an Organic Sensitizer and an Iron Porphyrin Catalyst.

Using a phenoxazine-based organic photosensitizer and an iron porphyrin molecular catalyst, we demonstrated photochemical reduction of CO to CO and CH with turnover numbers (TONs) of 149 and 29, respectively, under visible-light irradiation (λ > 435 nm) with a tertiary amine as sacrificial electron donor. This work is the first example of a molecular system using an earth-abundant metal catalyst and an organic dye to effect complete 8e/8H reduction of CO to CH, as opposed to typical 2e/2H products of CO or formic acid. The catalytic system continuously produced methane even after prolonged irradiation up to 4 days.

Visible-light Homogeneous Photocatalytic Conversion of CO into CO in Aqueous Solutions with an Iron Catalyst.

An iron-substituted tetraphenyl porphyrin bearing positively charged trimethylammonio groups at the para position of each phenyl ring catalyzes the photoinduced conversion of CO . This complex is water soluble and acts as a molecular catalyst to selectively reduce CO into CO under visible-light irradiation in aqueous solutions (acetonitrile/water=1:9 v/v) with the assistance of purpurin, a simple organic photosensitizer. CO is produced with a catalytic selectivity of 95 % and turnover number up to 120, illustrating the possibility of photocatalyzing the reduction of CO in aqueous solution by using visible light, a simple organic sensitizer coupled to an amine as a sacrificial electron donor, and an earth-abundant metal-based molecular catalyst.

Visible-light-driven methane formation from CO with a molecular iron catalyst.

Converting CO into fuel or chemical feedstock compounds could in principle reduce fossil fuel consumption and climate-changing CO emissions. One strategy aims for electrochemical conversions powered by electricity from renewable sources, but photochemical approaches driven by sunlight are also conceivable. A considerable challenge in both approaches is the development of efficient and selective catalysts, ideally based on cheap and Earth-abundant elements rather than expensive precious metals.

Non-sensitized selective photochemical reduction of CO to CO under visible light with an iron molecular catalyst.

A substituted tetraphenyl iron porphyrin, bearing positively charged trimethylammonio groups at the para position of each phenyl ring, demonstrates its ability as a homogeneous molecular catalyst to selectively reduce CO to CO under visible light irradiation in organic media without the assistance of a sensitizer and no competitive hydrogen evolution for several days.

Photocatalytic H2 generation based on noble-metal-free binuclear cobalt complexes using visible-light.

Two new binuclear cobalt complexes, namely {[Co(dmgH)(dmgH2)]2L1} (I) and {[Co(dmgH)(dmgH2)]2L2} (II) (dmgH = dimethylglyoximate monoanion; dmgH2 = dimethylglyoxime, L1 = 1,3-bis(4-pyridyl)propane), L2 = 1,3-bis(imidazol-1-ylmethyl)benzene), have been synthesized by the self-assembly of [Co(dmgH)(dmgH2)] and L1 or L2, respectively. An efficient photocatalytic system was constructed by combining a noble-metal-free cobalt complex as the catalyst with Eosin Y dye (EY(2-)) as the photosensitizer to give an efficient H2 generating system under visible-light irradiation (λ > 420 nm) using triethanolamine (TEOA) as a sacrificial electron donor. The maximum amount of H2 generated was 1013 TON for I and 1134 TON for II over a 2 h irradiation period (λ > 420 nm) under the conditions of pH 8.

Contributions of the visual ventral pathway to long-range apparent motion.

Objects displaced intermittently across the visual field will nonetheless give an illusion of continuous motion [called apparent motion (AM)] under many common conditions. It is believed that form perception is of minor importance in determining AM, and that AM is mediated by motion-sensitive areas in the "where" pathway of the cortex. However, form and motion typically interact in specific ways when natural objects move through the environment.