Structurally Asymmetric Ni-O-Mn Node in Metal-Organic Layers on Carbon Nitride Support for CO Photoreduction.

The Jahn-Teller (J-T) effect-induced lattice distortion presents an advantageous approach to tailor the electronic structure and CO adsorption properties of catalytic centers, consequently conferring desirable photocatalytic CO reduction activity and selectivity. Nevertheless, achieving precise J-T distortion control over catalytic sites to enhance CO adsorption/activation and target-product desorption remains a formidable challenge. In this work, we successfully induced J-T lattice distortion in neighboring Ni sites by exchanging high-spin Mn into Ni-O-Ni nodes.

Indium Oxide Layer Dual Functional Modified Bismuth Vanadate Photoanode Promotes Photoelectrochemical Oxidation of Water to Hydrogen Peroxide.

The photoelectrochemical (PEC) dual-electron pathway for water oxidation to produce hydrogen peroxide (HO) shows promising prospects. However, the dominance of the four-electron pathway leading to O evolution competes with this reaction, severely limiting the efficiency of HO production. Here, we report a InO passivator-coated BiVO (BVO) photoanode, which effectively enhances the selectivity and yield of HO production via PEC water oxidation.

Reducing Dielectric Confinement Effect Enhances Carrier Separation in Two-Dimensional Hybrid Perovskite Photocatalysts.

Two-dimensional organic-inorganic hybrid perovskites (OIHPs) with alternating structure of the organic and inorganic layers have a natural quantum well structure. The difference of dielectric constants between organic and inorganic layers in this structure results in the enhancement of dielectric confinement effect, which exhibits a large exciton binding energy and hinders the separation of electron-hole pairs. Herein, a strategy to reduce the dielectric confinement effect by narrowing the dielectric difference between organic amine molecule and [PbBr] octahedron is put forward.

Toward Functionality and Deactivation of Metal-Single-Atom in Heterogeneous Photocatalysts.

Single-atom heterogeneous catalysts (SAHCs) provide an enticing platform for understanding catalyst structure-property-performance relationships. The 100% atom utilization and adjustable local coordination configurations make it easy to probe reaction mechanisms at the atomic level. However, the progressive deactivation of metal-single-atom (MSA) with high surface energy leads to frequent limitations on their commercial viability.

Single-Atom based Metal-Organic Framework Photocatalysts for Solar-Fuel Generation.

The growing demand for fossil fuels and subsequent CO emissions prompted a search for alternate sources of energy and a reduction in CO. Photocatalysis driven by solar light has been found as a potential research area to tackle both these problems. In this direction, SAC@MOF (Single-atom loaded MOFs) photocatalysis is an emerging field and a promising technology.

Atomically Contacted CsBiBr QDs@UiO-66 Composite for Photocatalytic CO Reduction.

Metal halide perovskite quantum dots (QDs) are widely studied in the field of photocatalytic CO due to their strong light absorption and long carrier migration length. However, it can not exhibit high catalytic performance because of the radiative recombination and the lack of effective catalytic sites. Metal organic frameworks (MOFs) encapsulated QDs can not only solve the aforementioned problems, but also maintain their own unique characteristics with ultra-high specific surfaces area and abundant metal sites.

Advances and challenges in the modification of photoelectrode materials for photoelectrocatalytic water splitting.

With the increasing consumption of fossil fuels, the development of clean and renewable alternative fuels has become a top priority. Hydrogen (H) is an ideal primary clean energy source for its extremely high gravimetric energy density, carbon-free combustion, and abundant natural resources. Photoelectrocatalytic (PEC) water splitting is among the most promising approaches for converting sunlight and water into H.

In-Plane Palladium and Interplanar Copper Dual Single-Atom Catalyst in Bulk-Like Carbon Nitride for Cascade CO Photoreduction.

Dual single-atom catalysts (DSACs) are promising for breaking the scaling relationships and ensuring synergistic effects compared with conventional single-atom catalysts (SACs). Nevertheless, precise synthesis and optimization of DSACs with specific locations and functions remain challenging. Herein, dual single-atoms are specifically incorporated into the layer-stacked bulk-like carbon nitride, featuring in-plane three-coordinated Pd and interplanar four-coordinated Cu (Pd-Cu/b-CN) atomic sites, from both experimental results and DFT simulations.

Single-Atom Heterogeneous Catalysts: Human- and AI-Driven Platform for Augmented Designs, Analytics and Reality-Enabled Manufacturing.

Heterogeneous catalysts with targeted functionality can be designed with atomic precision, but it is challenging to retain the structure and performance upon the scaled-up manufacturing. Particularly challenging is to ensure the "atomic economy", where every catalytic site is most gainfully utilized. Given the emerging synergistic integration of human- and artificial intelligence (AI)-driven augmented designs (AD), augmented analytics (AA), and augmented reality manufacturing (AM) platforms, this minireview focuses on single-atom heterogeneous catalysts (SAHCs) and examines the current status, challenges, and future perspectives of translating atomic-level structural precision and data-driven discovery to next-generation industrial manufacturing.

Understanding the unique S-scheme charge migration in triazine/heptazine crystalline carbon nitride homojunction.

Understanding charge transfer dynamics and carrier separation pathway is challenging due to the lack of appropriate characterization strategies. In this work, a crystalline triazine/heptazine carbon nitride homojunction is selected as a model system to demonstrate the interfacial electron-transfer mechanism. Surface bimetallic cocatalysts are used as sensitive probes during in situ photoemission for tracing the S-scheme transfer of interfacial photogenerated electrons from triazine phase to the heptazine phase.

Effect of Functional Group Modifications on the Photocatalytic Performance of g-C N.

In recent years, photocatalysis has received increasing attention in alleviating energy scarcity and environmental treatment, and graphite carbon nitride (g-C N ) is used as an ideal photocatalyst. However, it still remains numerous challenges to obtain the desirable photocatalytic performance of intrinsic g-C N . Functional group functionalization, formed by introducing functional groups into the bulk structure, is one of the common modification techniques to modulate the carrier dynamics and increases the number of active sites, offering new opportunities to break the limits for structure-to-performance relationship of g-C N .

Functionalized MOF-Based Photocatalysts for CO Reduction.

Metal-organic frameworks (MOFs) materials have become a research forefront in the field of photocatalytic CO reduction attributed to their ultra-high specific surface area, adjustable structure, and abundant catalytic active sites. Particularly, MOFs can be facilely tuned to match CO photoreduction by utilizing post-modification of metal nodes, functionalization of organic linkers, and combination with other active materials. Herein, the recent advances in the construction strategy of MOF-based photocatalysts materials for CO reduction are highlighted.

Identification of the Active Sites on Metallic MoO Nano-Sea-Urchin for Atmospheric CO Photoreduction Under UV, Visible, and Near-Infrared Light Illumination.

We report an oxygen vacancy (V )-rich metallic MoO nano-sea-urchin with partially occupied band, which exhibits super CO (even directly from the air) photoreduction performance under UV, visible and near-infrared (NIR) light illumination. The V -rich MoO nano-sea-urchin displays a CH evolution rate of 12.2 and 5.

Alkali metal-modified crystalline carbon nitride for photocatalytic nitrogen fixation.

Alkali metal chlorides have been used as molten salts for further preparing crystalline carbon nitride, but the effect of alkali metal types on the properties of crystalline carbon nitride has not been systematically studied. Therefore, in this paper, a series of crystalline carbon nitride samples doped with different alkali metals were successfully prepared using LiCl-KCl, KCl-NaCl, LiCl-KCl-NaCl and LiCl-NaCl as molten salts: LK-HTCN (Li-K co-doping), KN-HCN (K-Na co-doping), LKN-HTCN (Li-K-Na co-doping) and LN-HTCN (Li-Na co-doping). The experimental results show that KN-HCN contains only the heptazine unit structure, while the other samples contain heptazine and triazine unit structures.

Highly Strained Bi-MOF on Bismuth Oxyhalide Support with Tailored Intermediate Adsorption/Desorption Capability for Robust CO Photoreduction.

Herein, using as-designed surface-mounted Bismuth-based metal-organic framework (Bi-MOF) on two-dimensional BiOBr support, as an operable platform for site-specific strain engineering to tailor the intermediate adsorption/desorption capability in CO photocatalytic conversion is proposed. Giant compressive strain up to 7.85 % is successfully induced on the surface-mounted Bi-MOF revealed by HRTEM images and geometric phase analysis as well as in situ Raman characterization, which largely downshifts the p band center of Bi nodes and intensifies their unsaturated state.

Site-Specific Electron-Driving Observations of CO -to-CH Photoreduction on Co-Doped CeO /Crystalline Carbon Nitride S-Scheme Heterojunctions.

Photoexcited dynamic modulation, maximizing the effective utilization of photoinduced electron-hole pairs, dominates the multiple electrons-involving reduction pathways for terminal CH evolution during CO photoreduction. Yet, the site-specific regulation of directional charge transfer by modification of an S-scheme heterojunction has seldom been discussed. Herein, an atomic-level tailoring strategy by anchoring single-atomic Co into CeO co-catalyst rather than carbon nitride supports, which can selectively favor CO -to-CH photoreduction, is reported.

Highly Efficient Photocatalytic Reduction of CO to CO by In Situ Formation of a Hybrid Catalytic System Based on Molecular Iron Quaterpyridine Covalently Linked to Carbon Nitride.

Efficient and selective photocatalytic CO reduction was obtained within a hybrid system that is formed in situ via a Schiff base condensation between a molecular iron quaterpyridine complex bearing an aldehyde function and carbon nitride. Irradiation (blue LED) of an CH CN solution containing 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole (BIH), triethylamine (TEA), Feqpy-BA (qpy-BA=4-([2,2':6',2'':6'',2'''-quaterpyridin]-4-yl)benzaldehyde) and C N resulted in CO evolution with a turnover number of 2554 and 95 % selectivity. This hybrid catalytic system unlocks covalent linkage of molecular catalysts with semiconductor photosensitizers via Schiff base reaction for high-efficiency photocatalytic reduction of CO , opening a pathway for diverse photocatalysis.

Dual-Single-Atom Tailoring with Bifunctional Integration for High-Performance CO Photoreduction.

Single-atom photocatalysis has been demonstrated as a novel strategy to promote heterogeneous reactions. There is a diversity of monoatomic metal species with specific functions; however, integrating representative merits into dual-single-atoms and regulating cooperative photocatalysis remain a pressing challenge. For dual-single-atom catalysts, enhanced photocatalytic activity would be realized through integrating bifunctional properties and tuning the synergistic effect.

Construction 0D/2D heterojunction by highly dispersed AgS quantum dots (QDs) loaded on the g-CN nanosheets for photocatalytic hydrogen evolution.

In recent years, the use of quantum dots (QDs) cocatalysts to improve the hydrogen evolution activity from the water splitting of photocatalysts has become a popular research topic. Herein, we successfully prepared a novel 0 dimension/2 dimension (0D/2D) heterojunction nanocomposite (denoted AgS quantum dots (QDs)/g-CN) with excellent photocatalytic performance by anchoring the AgS QDs cocatalyst on the surface of g-CN through a self-assembly strategy. AgS QDs with an average particle size of approximately 5.

State-of-the-art recent progress in MXene-based photocatalysts: a comprehensive review.

Recently, the emerging two-dimensional material MXene enjoys a high reputation due to its fascinating characteristics and shines in various research fields. Among them, MXene has received increasing attention and favor from the photocatalysis community due to its regular planar structure, outstanding metal conductivity, surface adjustable chemical properties, abundant derivatives, and excellent optical and thermal properties. There is no doubt that the introduction of MXene has endowed the photocatalytic system with extraordinary performance and has made an important impact in the field of advanced catalysis and chemical technology.

Carbon-Graphitic Carbon Nitride Hybrids for Heterogeneous Photocatalysis.

Polymeric graphitic carbon nitride (g-C N ) and various carbon materials have experienced a renaissance as viable alternates in photocatalysis due to their captivating metal-free features, favorable photoelectric properties, and economic adaptabilities. Although numerous efforts have focused on the integration of both materials with optimized photocatalytic performance in recent years, the direct parameters for this emerging enhancement are not fully summarized yet. Fully understanding the synergistic effects between g-C N and carbon materials on photocatalytic action is vital to further development of metal-free semiconductors in future studies.

Crystalline Carbon Nitride Supported Copper Single Atoms for Photocatalytic CO Reduction with Nearly 100% CO Selectivity.

Single metal atom photocatalysts have received widespread attention due to the rational use of metal resources and maximum atom utilization efficiency. In particular, N-rich amorphous g-CN is always used as a support to anchor single metal atoms. However, the enhancement of photocatalytic activity of g-CN by introducing a single atom is limited due to the bulk morphology and the excess defects of amorphous g-CN.

Single Ni Atoms Anchored on Porous Few-Layer g-C N for Photocatalytic CO Reduction: The Role of Edge Confinement.

It is greatly intriguing yet remains challenging to construct single-atomic photocatalysts with stable surface free energy, favorable for well-defined atomic coordination and photocatalytic carrier mobility during the photoredox process. Herein, an unsaturated edge confinement strategy is defined by coordinating single-atomic-site Ni on the bottom-up synthesized porous few-layer g-C N (namely, Ni -CN) via a self-limiting method. This Ni -CN system with a few isolated Ni clusters distributed on the edge of g-C N is beneficial to immobilize the nonedged single-atomic-site Ni species, thus achieving a high single-atomic active site density.

Amine-functionalized graphitic carbon nitride decorated with small-sized Au nanoparticles for photocatalytic CO reduction.

Amine-functionalized graphitic carbon nitride (g-CN) decorated with Au nanoparticles (CN/Au) was prepared by N plasma treatment of g-CN powders impregnated with HAuCl·3HO. Well-dispersed Au nanoparticles with a small particle size were deposited on g-CN nanosheets. In addition, the amino group was introduced into the CN/Au system.

Single Au Atoms Anchored on Amino-Group-Enriched Graphitic Carbon Nitride for Photocatalytic CO Reduction.

Owing to the maximum atom-utilization efficiency and excellent catalytic properties, Au single-atom catalysts (SACs) have been extensively studied in various catalytic systems. However, the performance of Au SACs in CO reduction has seldom been investigated. Herein, Au single atoms on amino-group-modified graphitic carbon nitride (U-ACN) was successfully synthesized through a mild and eco-friendly urea reduction method.