The Effect of Materials Architecture in TiO2 /MOF Composites on CO2 Photoreduction and Charge Transfer

An Appraisal for Providing Charge Transfer (CT) Through Synthetic Porous Frameworks for their Semiconductor Applications

In recent years, there has been considerable focus on the development of charge transfer (CT) complex formation as a means to modify the band gaps of organic materials. In particular, CT complexes alternate layers of aromatic molecules with donor (D) and acceptor (A) properties to provide inherent electrical conductivity. In particular, the synthetic porous frameworks as attractive D-A components have been extensively studied in recent years in comparison to existing D-A materials. Therefore, in this work, the synthetic porous frameworks are classified into conjugated microporous polymers (CMPs), covalent organic frameworks (COFs), and metal-organic frameworks (MOFs) and compare high-quality materials for CT in semiconductors. This work updates the overview of the above porous frameworks for CT, starting with their early history regarding their semiconductor applications, and lists CT concepts and selected key developments in their CT complexes and CT composites. In addition, the network formation methods and their functionalization are discussed to provide access to a variety of potential applications. Furthermore, several theoretical investigations, efficiency improvement techniques, and a discussion of the electrical conductivity of the porous frameworks are also highlighted. Finally, a perspective of synthetic porous framework studies on CT performance is provided along with some comparisons.

Catalyzing Artificial Photosynthesis with TiO2 Heterostructures and Hybrids: Emerging Trends in a Classical yet Contemporary Photocatalyst

Titanium dioxide (TiO2) stands out as a versatile transition-metal oxide with applications ranging from energy conversion/storage and environmental remediation to sensors and optoelectronics. While extensively researched for these emerging applications, TiO2 has also achieved commercial success in various fields including paints, inks, pharmaceuticals, food additives, and advanced medicine. Thanks to the tunability of their structural, morphological, optical, and electronic characteristics, TiO2 nanomaterials are among the most researched engineering materials. Besides these inherent advantages, the low cost, low toxicity, and biocompatibility of TiO2 nanomaterials position them as a sustainable choice of functional materials for energy conversion. Although TiO2 is a classical photocatalyst well-known for its structural stability and high surface activity, TiO2-based photocatalysis is still an active area of research particularly in the context of catalyzing artificial photosynthesis. This review provides a comprehensive overview of the latest developments and emerging trends in TiO2 heterostructures and hybrids for artificial photosynthesis. It begins by discussing the common synthesis methods for TiO2 nanomaterials, including hydrothermal synthesis and sol-gel synthesis. It then delves into TiO2 nanomaterials and their photocatalytic mechanisms, highlighting the key advancements that have been made in recent years. The strategies to enhance the photocatalytic efficiency of TiO2, including surface modification, doping modulation, heterojunction construction, and synergy of composite materials, with a specific emphasis on their applications in artificial photosynthesis, are discussed. TiO2-based heterostructures and hybrids present exciting opportunities for catalyzing solar fuel production, organic degradation, and CO2 reduction via artificial photosynthesis. This review offers an overview of the latest trends and advancements, while also highlighting the ongoing challenges and prospects for future developments in this classical yet rapidly evolving field.

Boosting hydrogen production of a MOF-based multicomponent photocatalyst with clean interface via facile one-pot electrosynthesis

Hydrogen production from photocatalysis via the usage of multicomponent photocatalysts represents a promising pathway for carbon peaking and carbon neutrality, owing to their structural advantages in dealing with the three crucial processes in photocatalysis, namely, light harvesting, charge transfer, and surface redox reactions. We demonstrate the fabrication of a MOF-based multicomponent photocatalyst, denoted as semiconductor/MOF/cocatalyst, by a one-pot electrochemical synthetic route. The as-fabricated multicomponent photocatalyst has a clean interface among the components, leading to close connections that contribute to high-quality heterojunction and facilitate photogenerated charge transfer and separation, thereby the efficient hydrogen evolution. The hydrogen production rate of the resultant ZrO2 /Zr-MOF/Pt is 1327 μmol ⋅ g-1  ⋅ h-1 , which is much higher than that of ZrO2 /Zr-MOF (15 μmol ⋅ g-1  ⋅ h-1 ) and pure Zr-MOF (10.1 μmol ⋅ g-1  ⋅ h-1 ), as well as the photodeposited-Pt products ZrO2 /Zr-MOF/PtPD (287 μmol ⋅ g-1  ⋅ h-1 ) and Zr-MOF/PtPD (192 μmol ⋅ g-1  ⋅ h-1 ) obtained by the step-wise synthetic approach. The work gives a good inspiration for the rational design and construction of MOF-based multicomponent photocatalysts through the one-pot electrosynthesis.

Electronic Structure Engineered Heteroatom Doped All Transition Metal Sulfide Carbon Confined Heterostructure for Extrinsic Pseudocapacitor

Ultra-high energy density battery-type materials are promising candidates for supercapacitors (SCs); however, slow ion kinetics and significant volume expansion remain major barriers to their practical applications. To address these issues, hierarchical lattice distorted α-/γ-MnS@Cox Sy core-shell heterostructure constrained in the sulphur (S), nitrogen (N) co-doped carbon (C) metal-organic frameworks (MOFs) derived nanosheets (α-/γ-MnS@Cox Sy @N, SC) have been developed. The coordination bonding among Cox Sy , and α-/γ-MnS nanoparticles at the interfaces and the π-π stacking interactions developed across α-/γ-MnS@Cox Sy and N, SC restrict volume expansion during cycling. Furthermore, the porous lattice distorted heteroatom-enriched nanosheets contain a sufficient number of active sites to allow for efficient electron transportation. Density functional theory (DFT) confirms the significant change in electronic states caused by heteroatom doping and the formation of core-shell structures, which provide more accessible species with excellent interlayer and interparticle conductivity, resulting in increased electrical conductivity. . The α-/γ-MnS@Cox Sy @N, SC electrode exhibits an excellent specific capacity of 277 mA hg-1 and cycling stability over 23 600 cycles. A quasi-solid-state flexible extrinsic pseudocapacitor (QFEPs) assembled using layer-by-layer deposited multi-walled carbon nanotube/Ti3 C2 TX nanocomposite negative electrode. QFEPs deliver specific energy of 64.8 Wh kg-1 (1.62 mWh cm-3 ) at a power of 933 W kg-1 and 92% capacitance retention over 5000 cycles.

Microwave-Assisted Rapid Substitution of Ti for Zr to Produce Bimetallic (Zr/Ti)UiO-66-NH2 with Congenetic "Shell-Core" Structure for Enhancing Photocatalytic Removal of Nitric Oxide

Efficient nitric oxide (NO) removal without nitrogen dioxide (NO₂ ) emission is desired for the control of air pollution. Herein, a series of (Zr/Ti)UiO-66-NH₂ with congenetic shell-core structure, denoted as Ti-UION, are rapidly synthesized by microwave-assisted post-synthetic modification for NO removal. The optimal Ti-UION (i.e., 2.5Ti-UION) exhibits the highest activity of 80.74% without NO₂ emission with moisture, which is 21.65% greater than that of the UiO-66-NH₂ . The NO removal efficiency of 2.5Ti-UION further increases to 95.92% without photocatalyst deactivation under an anhydrous condition. This is because selectively produced NO₂ in photocatalysis is completely adsorbed into micropores, refreshing active sites for subsequent reaction. In addition, the enhanced photocatalytic activity after Ti substitution is due to the presence of Ti electron acceptor, the potential difference between the shell and core of Ti-UION crystal, and the high conductivity of TiO units. Additionally, the improved adsorption of gas molecules not only favors NO oxidation, but also avoids the emission of NO₂ . This work provides a feasible strategy for rapid metal substitution in metal-organic frameworks and insights into enhanced NO photodegradation.

MOF-Derived Defective Co3O4 Nanosheets in Carbon Nitride Nanocomposites for CO2 Photoreduction and H2 Production

In photocatalysis, especially in CO₂ reduction and H₂ production, the development of multicomponent nanomaterials provides great opportunities to tune many critical parameters toward increased activity. This work reports the development of tunable organic/inorganic heterojunctions comprised of cobalt oxides (Co₃O₄) of varying morphology and modified carbon nitride (CN), targeting on optimizing their response under UV-visible irradiation. MOF structures were used as precursors for the synthesis of Co₃O₄. A facile solvothermal approach allowed the development of ultrathin two-dimensional (2D) Co₃O₄ nanosheets (Co₃O₄-NS). The optimized CN and Co₃O₄ structures were coupled forming heterojunctions, and the content of each part was optimized. Activity was significantly improved in the nanocomposites bearing Co₃O₄-NS compared with the corresponding bulk Co₃O₄/CN composites. Transient absorption spectroscopy revealed a 100-fold increase in charge carrier lifetime on Co₃O₄-NS sites in the composite compared with the bare Co₃O₄-NS. The improved photocatalytic activity in H₂ production and CO₂ reduction is linked with (a) the larger interface imposed from the matching 2D structure of Co₃O₄-NS and the planar surface of CN, (b) improvements in charge carrier lifetime, and (c) the enhanced CO₂ adsorption. The study highlights the importance of MOF structures used as precursors in forming advanced materials and the stepwise functionalization of the individual parts in nanocomposites for the development of materials with superior activity.

Optimization of Fe/Ni organic frameworks with core-shell structures for efficient visible-light-driven reduction of carbon dioxide to carbon monoxide

To address CO₂ emissions caused by the overuse of fossil fuels, photocatalytic CO₂ reduction from metal-organic frameworks (MOFs) to valuable chemicals is critical for energy conversion and storage. Core-shell MOFs improve interfacial interactions, increasing the number of active sites in the catalyst, thereby improving the photocatalytic reduction. In this work, the catalytic performance of Fe/Ni-MOFs toward photocatalytic CO₂ reduction was improved using a bimetallic strategy. We successfully synthesized a series of Fe/Ni-MOFs with a core-shell structure using a single-step approach combined with hydrothermal synthesis. By altering the synthesis conditions of the bimetallic organic skeleton and contrasting it with a single MOF, we successfully synthesized Fe/Ni-T120 through an efficient photocatalytic reduction of CO₂. The results of photocatalytic CO₂ reduction experiments indicated that upon using [Ru(bpy)₃]Cl₂·6H₂O as a photosensitizer and triethanolamine (TEOA) and acetonitrile (MeCN) as sacrificial agents, the CO evolution rate of Fe/Ni-T120 reached 9.74 mmol g^-1 h^-1 and the CO₂ to CO selectivity reached up to 92.1%. Additionally, Fe/Ni-T120 has a broad response range to visible light, a high photocurrent intensity, good chemical stability, and strong photocatalytic efficiency, even after repeated cycles. This study proposes a straightforward method for producing adaptable and stable MOFs for effective photocatalytic CO₂ reduction that is driven by visible light.

Preparation and modification methods of defective titanium dioxide-based nanoparticles for photocatalytic wastewater treatment-a comprehensive review

The rapid population growth and industrial expansion worldwide have created serious water contamination concerns. To curb the pollution issue, it has become imperative to use a versatile material for the treatment. Titanium dioxide (TiO₂) has been recognized as the most-studied nanoparticle in various fields of science and engineering due to its availability, low cost, efficiency, and other fascinating properties with a wide range of applications in modern technology. Recent studies revealed the photocatalytic activity of the material for the treatment of industrial effluents to promote environmental sustainability. With the wide band gap energy of 3.2 eV, TiO₂ can be activated under UV light; thus, many strategies have been proposed to extend its photoabsorption to the visible light region. In what follows, this has generated increasing attention to study its characteristics and structural modifications in different forms for photocatalytic applications. The present review provides an insight into the understanding of the synthesis methods of TiO₂, the current progress in the treatment techniques for the degradation of wide environmental pollutants employing modified TiO₂ nanoparticles, and the factors affecting its photocatalytic activities. Further, recent developments in using titania for practical applications, the approach for designing novel nanomaterials, and the prospects and opportunities in this exciting area have been discussed.

Adsorption of Methyl Orange on a Novel Palygorskite/UiO-66 Nanocomposite

Herein, a novel composite material containing UiO-66 and palygorskite (Pal) clay mineral was prepared using a facile one-pot synthesis process. The material was studied using a variety of techniques and applied as did not affect the structure of the metal-organic framework (MOF) part, but induced a small increase in specific surface area. The developed Pal/UiO-66 composite presented excellent adsorption efficiency against MO removal, as evidenced by detailed kinetic and isotherm experiments. An impressive maximum adsorption capacity at equilibrium was evidenced; 340 mg g−1 at pH = 5 and T = 25 °C. This corresponds to a 34.5 % increase compared with pure UiO-66, considering only the MOF content. Furthermore, the Pal/UiO-66 composite was proven stable and highly recyclable, losing less than 9% of the removal capacity after five consecutive cycles. The study highlights the synergistic effect of the coupling of MOF structures with low-cost and abundant clay minerals for the development of advanced absorbents.

Effect of Band Bending in Photoactive MOF-Based Heterojunctions

Semiconductor/metal-organic framework (MOF) heterojunctions have demonstrated promising performance for the photoconversion of CO₂ into value-added chemicals. To further improve performance, we must understand better the factors which govern charge transfer across the heterojunction interface. However, the effects of interfacial electric fields, which can drive or hinder electron flow, are not commonly investigated in MOF-based heterojunctions. In this study, we highlight the importance of interfacial band bending using two carbon nitride/MOF heterojunctions with either Co-ZIF-L or Ti-MIL-125-NH₂. Direct measurement of the electronic structures using X-ray photoelectron spectroscopy (XPS), work function, valence band, and band gap measurements led to the construction of a simple band model at the heterojunction interface. This model, based on the heterojunction components and band bending, enabled us to rationalize the photocatalytic enhancements and losses observed in MOF-based heterojunctions. Using the insight gained from a promising band bending diagram, we developed a Type II carbon nitride/MOF heterojunction with a 2-fold enhanced CO₂ photoreduction activity compared to the physical mixture.

A Conductive Network and Dipole Field for Harnessing Photogenerated Charge Kinetics

Photogenerated charge separation and directional transfer to active sites are pivotal steps in photocatalysis, which limit the efficiency of redox reactions. Here, a conductive network and dipole field are employed to harness photogenerated charge kinetics by using a Ti₃ C₂ /TiO₂ network (TTN). The TTN exhibits a prolonged charge-carrier lifetime (1.026 ns) and an 11.76-fold increase in hexavalent chromium photoreduction reaction kinetics compared to TiO₂ nanoparticles (TiO₂ NPs). This super photocatalytic performance is derived from the efficient photogenerated charge kinetics, which is steered by the conductive network and dipole field. The conductivity enhancement of the TiO₂ network is achieved by continuous chemical bonds, which promotes electron-hole (e-h) separation. In addition, at the interface of Ti₃ C₂ and TiO₂ , band bending induced by the dipole field promotes photogenerated electron spatially directed transfer to the catalytic sites on Ti₃ C₂ . This study demonstrates that a conductive network and dipole field offer a new concept to harness charge kinetics for photocatalysis.

In situ Irradiated XPS Investigation on S-Scheme TiO2 @ZnIn2 S4 Photocatalyst for Efficient Photocatalytic CO2 Reduction

Reasonable design of efficient hierarchical photocatalysts has gained significant attention. Herein, a step-scheme (S-scheme) core-shell TiO₂ @ZnIn₂ S₄ heterojunction is designed for photocatalytic CO₂ reduction. The optimized sample exhibits much higher CO₂ photoreduction conversion rates (the sum yield of CO, CH₃ OH, and CH₄ ) than the blank control, i.e., ZnIn₂ S₄ and TiO₂ . The improved photocatalytic performance can be attributed to the inhibited recombination of photogenerated charge carriers induced by S-scheme heterojunction. The improvement is also attributed to the large specific surface areas and abundant active sites. Meanwhile, S-scheme photogenerated charge transfer mechanism is testified by in situ irradiated X-ray photoelectron spectroscopy, work function calculation, and electron paramagnetic resonance measurements. This work provides an effective strategy for designing highly efficient heterojunction photocatalysts for conversion of solar fuels.

In Situ Porphyrin Substitution in a Zr(IV)-MOF for Stability Enhancement and Photocatalytic CO2 Reduction

Despite numerous inherent merits of metal-organic frameworks (MOFs), structural fragility has imposed great restrictions on their wider involvement in many applications, such as in catalysis. Herein, a strategy for enhancing stability and enabling functionality in a labile Zr(IV)-MOF has been proposed by in situ porphyrin substitution. A size- and geometry-matched robust linear porphyrin ligand 4,4'-(porphyrin-5,15-diyl)dibenzolate (DCPP^2- ) is selected to replace the 4,4'-(1,3,6,8-tetraoxobenzo[lmn][3,8]phenanthroline-2,7(1H,3H,6H,8H)-diyl)dibenzoate (NDIDB^2- ) ligand in the synthesis of BUT-109(Zr), affording BUT-110 with varied porphyrin contents. Compared to BUT-109(Zr), the chemical stability of BUT-110 series is greatly improved. Metalloporphyrin incorporation endows BUT-110 MOFs with high catalytic activity in the photoreduction of CO₂ , in the absence of photosensitizers. By tuning the metal species and porphyrin contents in BUT-110, the resulting BUT-110-50%-Co is demonstrated to be a good photocatalyst for selective CO₂ -to-CO reduction, via balancing the chemical stability, photocatalytic efficiency, and synthetic cost. This work highlights the advantages of in situ ligand substitution for MOF modification, by which uniform distribution and high content of the incoming ligand are accessible in the resulting MOFs. More importantly, it provides a promising approach to convert unstable MOFs, which mainly constitute the vast MOF database but have always been neglected, into robust functional materials.

A butterfly shaped organic heterojunction photocatalyst for effective photocatalytic CO2 reduction

The modification of carbon nitride (CN) for visible light photocatalytic CO₂ reduction is an important issue to explore in the context of energy and environmental challenges.

Metal oxide integrated metal organic frameworks (MO@MOF): rational design, fabrication strategy, characterization and emerging photocatalytic applications

This review focuses on the possible synthesis route, characterization techniques, and mechanistic pathways involved in the photocatalytic applications of MO@MOFs.

Synthesis of TiO2/Nanozeolite Composites for Highly Efficient Photocatalytic Oxidation of Propene in the Gas Phase

In this work, we reported the preparation of composites based on titania (TiO2) and Zeolite Socony Mobil-5 (ZSM-5) nanozeolite, following two approaches (i.e., incorporating the presynthesized zeolite in the synthesis medium of TiO2 and incorporating presynthesized TiO2 in the synthesis medium of ZSM-5). The materials synthesized were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), nitrogen adsorption, X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) spectrometry analysis, and their photocatalytic activities were assessed in the oxidation of propene in the gas phase. It was observed that the synthesis methodology affects the final properties of the composite, which ultimately affected their photocatalytic performance in the studied application. It was found that the Nano-ZSM5/TiO2 composite was the most active among the investigated samples, which was attributed to the intimate contact between the two components of the composite, the preserved properties of the photocatalytic active phase in the final material, and the positive contribution of the nanozeolite by increasing the local concentration of propene.

Direct Z-Scheme Heterojunction of SnS2 /Sulfur-Bridged Covalent Triazine Frameworks for Visible-Light-Driven CO2 Photoreduction

Solar-driven reduction of CO₂ into renewable carbon forms is considered as an alternative approach to address global warming and the energy crisis but suffers from low efficiency of the photocatalysts. Herein, a direct Z-Scheme SnS₂ /sulfur-bridged covalent triazine frameworks (S-CTFs) photocatalyst (denoted as SnS₂ /S-CTFs) was developed, which could efficiently adsorb CO₂ owing to the CO₂ -philic feature of S-CTFs and promote separation of photoinduced electron-hole pairs. Under visible-light irradiation, SnS₂ /S-CTFs exhibited excellent performance for CO₂ photoreduction, yielding CO and CH₄ with evolution rates of 123.6 and 43.4 μmol g^-1  h^-1 , respectively, much better than the most catalysts reported to date. This inorganic/organic hybrid with direct Z-Scheme structure for visible-light-driven CO₂ photoreduction provides new insights for designing photocatalysts with high efficiency for solar-to-fuel conversion.

Activity and selectivity of CO2 photoreduction on catalytic materials

Photoreduction of molecular CO₂ by solar light into added-value fuels or chemical feedstocks is an appealing strategy to simultaneously overcome environmental problems and energy challenges. However, multiple reaction steps and a large number of possible products have significantly hindered the development of highly selective catalysts capable of delivering CO₂ conversion with high efficiency. Recently, several strategies associated with different conversion mechanisms have been proposed to improve the activity and product selectivity of CO₂ photocatalysts. These are based on development of low dimensional nanomaterials, defect or facet engineering, design of tailored heterostructures, and carrier conductivity enhancement. In spite of impressive progress in the field, real-world applications are yet to be delivered. To sustain further research in this promising field, here we provide a short frontier of recent advances in activity and selectivity of CO₂ reduction photocatalysts, together with a critical discussion of further avenues of research in this field.

Highly Selective Photoreduction of CO2 with Suppressing H2 Evolution by Plasmonic Au/CdSe-Cu2 O Hierarchical Nanostructures under Visible Light

Here, the photocatalytic CO₂ reduction reaction (CO₂ RR) with the selectivity of carbon products up to 100% is realized by completely suppressing the H₂ evolution reaction under visible light (λ > 420 nm) irradiation. To target this, plasmonic Au/CdSe dumbbell nanorods enhance light harvesting and produce a plasmon-enhanced charge-rich environment; peripheral Cu₂ O provides rich active sites for CO₂ reduction and suppresses the hydrogen generation to improve the selectivity of carbon products. The middle CdSe serves as a bridge to transfer the photocharges. Based on synthesizing these Au/CdSe-Cu₂ O hierarchical nanostructures (HNSs), efficient photoinduced electron/hole (e^- /h⁺ ) separation and 100% of CO selectivity can be realized. Also, the 2e^- /2H⁺ products of CO can be further enhanced and hydrogenated to effectively complete 8e^- /8H⁺ reduction of CO₂ to methane (CH₄ ), where a sufficient CO concentration and the proton provided by H₂ O reduction are indispensable. Under the optimum condition, the Au/CdSe-Cu₂ O HNSs display high photocatalytic activity and stability, where the stable gas generation rates are 254 and 123 µmol g^-1 h^-1 for CO and CH₄ over a 60 h period.

Photosensitive Hybrid Nanostructured Materials: The Big Challenges for Sunlight Capture

Solar radiation is becoming increasingly appreciated because of its influence on living matter and the feasibility of its application for a variety of purposes. It is an available and everlasting natural source of energy, rapidly gaining ground as a supplement and alternative to the nonrenewable energy feedstock. Actually, an increasing interest is involved in the development of efficient materials as the core of photocatalytic and photothermal processes, allowing solar energy harvesting and conversion for many technological applications, including hydrogen production, CO2 reduction, pollutants degradation, as well as organic syntheses. Particularly, photosensitive nanostructured hybrid materials synthesized coupling inorganic semiconductors with organic compounds, and polymers or carbon-based materials are attracting ever-growing research attention since their peculiar properties overcome several limitations of photocatalytic semiconductors through different approaches, including dye or charge transfer complex sensitization and heterostructures formation. The aim of this review was to describe the most promising recent advances in the field of hybrid nanostructured materials for sunlight capture and solar energy exploitation by photocatalytic processes. Beside diverse materials based on metal oxide semiconductors, emerging photoactive systems, such as metal-organic frameworks (MOFs) and hybrid perovskites, were discussed. Finally, future research opportunities and challenges associated with the design and development of highly efficient and cost-effective photosensitive nanomaterials for technological claims were outlined.

Recent Innovation of Metal-Organic Frameworks for Carbon Dioxide Photocatalytic Reduction

The accumulation of carbon dioxide (CO2) pollutants in the atmosphere begets global warming, forcing us to face tangible catastrophes worldwide. Environmental affability, affordability, and efficient CO2 metamorphotic capacity are critical factors for photocatalysts; metal-organic frameworks (MOFs) are one of the best candidates. MOFs, as hybrid organic ligand and inorganic nodal metal with tailorable morphological texture and adaptable electronic structure, are contemporary artificial photocatalysts. The semiconducting nature and porous topology of MOFs, respectively, assists with photogenerated multi-exciton injection and adsorption of substrate proximate to void cavities, thereby converting CO2. The vitality of the employment of MOFs in CO2 photolytic reaction has emerged from the fact that they are not only an inherently eco-friendly weapon for pollutant extermination, but also a potential tool for alleviating foreseeable fuel crises. The excellent synergistic interaction between the central metal and organic linker allows decisive implementation for the design, integration, and application of the catalytic bundle. In this review, we presented recent MOF headway focusing on reports of the last three years, exhaustively categorized based on central metal-type, and novel discussion, from material preparation to photocatalytic, simulated performance recordings of respective as-synthesized materials. The selective CO2 reduction capacities into syngas or formate of standalone or composite MOFs with definite photocatalytic reaction conditions was considered and compared.