Abstract Particulate Z-scheme overall water splitting holds considerable promise for solar hydrogen production, yet its potential is persistently constrained by mediator-involved reverse reactions and related interfacial charge loss. Here we show that water-splitting reactions and parasitic mediator redox can be spatially decoupled across microscale surface domains, thereby suppressing reverse chemistry at its origin. Using facet-engineered Y2Ti2O5S2 and BiVO4 microcrystals as H2-evolving and O2-evolving photocatalysts, respectively, anisotropic charge separation together with facet-selective mediator adsorption directs mediator redox to specific facets, while H2 and O2 evolution proceed on the lateral facets of both photocatalysts. This spatially organized interfacial architecture separates forward and parasitic pathways within individual particles, suppressing mediator self-cycling and H2/O2 recombination without hindering productive interparticle charge transfer. Consequently, visible-light-driven overall water splitting activity is enhanced by over 60-fold relative to the nonfaceted counterpart, delivering an apparent quantum yield of 17.1% at 420 nm, a solar-to-hydrogen efficiency exceeding 1.0%, and sustained activity near atmospheric pressure. These findings establish spatial decoupling of interfacial redox sites as a general design principle for mitigating reverse reactions in Z-scheme artificial photosynthesis for solar hydrogen production.

In recent years, numerous photocatalytic systems have been developed to promote a wide range of organic transformations mediated by singlet oxygen. However, conventional blue-light photosensitizers encounter significant challenges in large-scale synthesis, primarily due to the limited penetration depth of high-energy photons. Herein, we report an atomically precise Au27 nanocluster featuring a novel superatomic core built from an icosahedral Au13 and a tetrahedral Au4, allowing for highly efficient singlet oxygen generation under far-red-light irradiation. While its overall structure closely resembles that of Au25 nanoclusters with a single icosahedral Au13 core, the incorporation of a tetrahedral Au4 building unit through ligand engineering markedly enhances intersystem crossing efficiency and aligns transition energies for effective O2 sensitization, affording an internal quantum yield of 0.37% at 740 nm. Compared with previous light-driven systems, our ten-gram-scale, cluster-based photochemical process reduces catalyst loading by four orders of magnitude (10,000-fold), requiring only 13 nmol of photocatalyst, and achieves turnover numbers greater than one million. This study establishes a new paradigm in photocatalyst design, demonstrating how atomic-level structural control can enable far-red-light-driven organic transformations with substantially enhanced catalytic performance.

Structural supercapacitors employing carbon fiber (CF)-based electrodes offer simultaneous load-bearing capability and energy storage, making them highly attractive for portable electronics and electric vehicles. However, the inherently low specific surface area of as-received CF significantly restricts the electrochemical performance of such devices. In this work, vertical carbon nanosheets (VCN) were grown on the CF surface, followed by the introduction of heteroatom-doped porous carbon (HDPC) derived from polyphosphazene with the assistance of a biomass-derived binder, forming a novel CF-based electrode through a synergistic modification strategy. Structural supercapacitors were subsequently assembled using the co-modified CF electrodes, a separator, and a homogeneous polymer electrolyte, and their electrochemical and mechanical properties were systematically evaluated. The results demonstrate that the specific surface area and electrochemical activity of the activated carbon materials modified (CF)-based electrode were significantly enhanced, yielding a maximum areal capacitance of 146.0 mF cm(-2) of structural supercapacitors. Meanwhile, the fabricated structural super-capacitor exhibits a flexural strength of 21.2 MPa and a flexural modulus of 1.6 GPa. Notably, the incorporation of biomass materials as a binder provides a sustainable and effective pathway for developing high-performance structural supercapacitors.

A fundamental obstacle in photocatalytic overall water splitting lies in the simultaneous evolution of H2 and O2 gases, which complicates gas separation. Decoupling hydrogen and oxygen evolution via a redox electron mediator offers an attractive route to overcome this limitation; however, its success critically depends on the development of electron mediators that satisfy both suitable redox potentials and rapid interfacial charge-transfer kinetics. Here, we demonstrate tunable redox potential in cobalt bipyridine complexes, [Co(bpy)2Cl2]Cl, through ligand functionalization. Electron-donating groups (-OCH3, -CH3) induce negative shifts in the redox potential, whereas electron-withdrawing substituents (-Cl) leads to positive shifts, yielding a broad potential range from 0.15 to 0.62 V versus NHE. The optimized electron mediator, [Co(bpy-CH3)2Cl2]Cl, exhibits enhanced electron transfer and water oxidation activity on BiVO4 photocatalyst. Coupled with selective assembling of Pt on the electron-rich {010} facets, an Pt-Cl interfacial charge-transfer channel was established, which accelerates electron transfer and promotes the adsorption/desorption of electron mediator. This integrated system achieves efficient photocatalytic water oxidation with an apparent quantum efficiency of up to 90% at 420 nm. Using [Co(bpy-CH3)2Cl2]Cl electron mediator, the work demonstrated the spatial separation of hydrogen and oxygen evolution reactions in particulate photocatalytic water splitting.

Abstract A photocatalytic process involves the intricate integration of complex photophysical and photochemical events that occur at nanoscale interfaces and evolve over femtoseconds to second scales. However, directly tracking the nanoscale carrier dynamics of a single photocatalyst crystal under the reaction conditions is essential but remains challenging. Here, we employed in-situ transient reflection microscopy to spatiotemporally resolve the evolution of photogenerated carriers in facet-engineered bismuth vanadate (BiVO4) photocatalyst. It is revealed that photogenerated holes undergo three sequential steps: initial ultrafast charge separation (~5 ps), hole trapping (~1.5 ns), and trap states-mediated interfacial transfer to pre-adsorbed H2O on the surface (~19 ps). Crucially, trap states associated with oxygen lattice sites act as nanoscale relay sites that enable rapid hole injection into pre-adsorbed H2O, whereas direct valence-band hole injection is negligible. These findings provide a comprehensive mechanistic picture of photogenerated carrier dynamics across the entire photocatalytic process, directly linking nanostructure to interfacial chemistry and revealing trap states as critical mediators of efficient interfacial charge transfer.

Bismuth vanadate (BiVO4) exhibits significant potential for Photoelectrochemical (PEC) water splitting owing to its suitable bandgap alignment and cost efficiency. However, its practical performance is constrained by inefficient charge transport and severe carrier recombination. Herein, a facile thiourea (CH4N2S) etching strategy is employed to fabricate S, N co-doped BiVO4 (SN-BiVO4). A variable voltage electron probe microanalysis (EPMA) is proposed for detecting elemental distribution, cross-validated with X-ray photoelectron spectroscopy (XPS). Combining kinetics analysis and density functional theory (DFT) calculations, it is found that SN-BiVO4 forms S gradient doping along the depth direction, forming continuous regulation of energy bands and improving the carrier separation ability. Furthermore, surface N enrichment promotes the formation of surface oxygen vacancies (Ovac), which modulate the surface electron density and significantly accelerate the kinetics of water oxidation. Under the synergistic effect, SN-BiVO4 reaches a remarkable photocurrent density of 3.03 mA cm- 2 at 1.23 V vs. RHE without cocatalyst, which is 2.9 times that of BiVO4. After loading NiFePx cocatalyst and constructing an unbiased solar water splitting system with Si solar cell, a solar-to-hydrogen conversion efficiency (STH) of 5.52% can be achieved while showing robust stability. This work provides a universal element codoping strategy and opens up new perspectives for understanding the synergistic co-doping effects.

The emergence of functional hydrogen-bonded organic frameworks (HOFs) has created new opportunities in materials science. However, the development of functional metallo-HOFs (MHOFs) featuring switchable magnetic properties remains a significant challenge. Herein, we report three new magnetic MHOFs built from spin-crossover (SCO)-active [Fe(2-pic)3]2+ cation and two sulfonate anions, 1,5-naphthalenedisulfonate (NDS2-) and 1,3,6,8-pyrenetetrasulfonate (PTS4-). These compounds, formulated as [Fe(2-pic)3]·NDS·2H2O (1·2H2O) and [Fe(2-pic)3]·0.5PTS·nH2O (n = 2, 3; denoted as 2·2H2O and 3·3H2O), were fully characterized by single-crystal X-ray diffraction, magnetic measurements, and proton conduction studies. Notably, complex 1·2H2O undergoes a single-crystal-to-single-crystal transformation upon dehydration, which directly modifies its hydrogen-bonded network, thereby switching its gradual and complete SCO to a fully HS state. Complexes 2·2H2O and 3·3H2O exhibit distinct SCO profiles due to their different Fe2+ coordination geometries (meridional in 2·2H2O, facial in 3·3H2O) and hydrogen-bonded networks. While 2·2H2O exhibits a gradual two-step SCO, 3·3H2O displays hysteresis SCO with a loop width of approximately 10 K. Proton conduction studies revealed that these complexes show moderate proton conduction (with σ up to 2.70 × 10-3 S cm-1 at 95% RH and 45 °C), with 3·3H2O performing the best. These complexes represent rare multifunctional MHOFs integrating switchable SCO and proton transport.

Photocatalytic overall water splitting remains limited by inefficient charge separation and utilization in reactions. Al-doped SrTiO3 exhibiting near-100% apparent quantum efficiency for overall water splitting indicates nearly complete charge separation and surface catalytic efficiency. Although Al doping has been assumed to enhance charge separation and transfer, the exact role of Al is still unclear. Here, using spatiotemporal surface photovoltage imaging, we show that a gradient Al doping in Al-doped SrTiO3 generates a built-in electric field that drives photogenerated holes from the bulk toward surface trap sites in the form of hydroxylated Al-O-Ti, prolonging their lifetime from ~100 ns to 10 ms. Spectroscopic analyses reveal that these hydroxylated Al sites serve as key centers for water adsorption, facilitating water oxidation. These findings underscore the pivotal role of Al in the spatiotemporal alignment of hole transfer and surface catalytic water oxidation, enabling high-efficiency photocatalysis in overall water splitting.

By employing a simple and readily available chiral difluorphos ligand, a highly enantioselective rhodium-catalyzed asymmetric arylation tandem cyclization of heteroatom-containing alkyne-tethered aliphatic ketones with boronic acids was achieved under mild conditions. This protocol offers efficient and practical access to a broad spectrum of chiral heterocyclic tertiary allylic alcohols bearing trisubstituted or tetrasubstituted alkene functionality in good yields (up to 86%) with excellent enantioselectivities (up to 99% ee). Moreover, the synthetic utility of this methodology has been demonstrated via the rapid and concise construction of various structurally intriguing chiral heterocyclic architectures.

The efficient catalytic conversion of toxic N2O and CO into harmless products is critical for environmental protection. Herein, we perform first-principles calculations to comparatively study CO-assisted N2O reduction over transition metal single-atom and dual-atom catalysts supported on CeO2 (111) surfaces and nanotubes (NTs). All investigated metal species can be stably anchored on both CeO2 supports, and some of the catalysts exhibit much stronger adsorption toward N2O than CO, showing excellent anti-CO-poisoning performance. The reaction proceeds via N2O decomposition into N2 and O* intermediate, followed by CO oxidation to CO2, with two key transition states corresponding to N2 desorption and CO2 desorption. Remarkably, V, Ta, V-V and V-Nb on CeO2 (111) surface enable effectively barrierless N2O decomposition followed by near-spontaneous N2 desorption, while the same metal species on CeO2 NTs also achieve effectively barrierless N2O decomposition but retain a modest N2 desorption barrier (0.64 ∼ 1.07 eV). CeO2 surface-supported catalysts show superior overall reaction activity, while CeO2 NT systems exhibit much higher N2O adsorption selectivity against impurity gases. The V-family/CeO2 system is concluded to be a promising candidate for efficient N2O decomposition.

Artificial metalloenzymes (ArMs) and photoenzymatic catalysis represent two cutting-edge approaches to creating new enzyme reactivity. However, the potential of merging these two strategies remains underdeveloped for enantiocontrolled biotransformations. Herein, we develop a synergistic metalloenzymatic and photoredox catalysis platform to enable enantiodivergent radical alkylation of 2-acyl imidazoles. Specifically, cupin proteins are redesigned to function as copper(II)-based Lewis-acid-enzymes (LAses), which, in synergy with tripyridinyl-ruthenium-based photoredox catalysis, precisely control the generation, reactivity, and selectivity of abiological radicals, thereby unlocking non-natural enzyme reactivity. Powered by protein engineering, repurposed photo-LAses facilitate the green and efficient synthesis of diverse enantioenriched α-chiral ketones in high enantioselectivity (both enantiomers accessible, up to 97% yield and 98.5:1.5 enantiomeric ratio [er]). Detailed mechanistic studies suggest a radical addition to the metalloenzymatic enolate pathway and explain the switched selectivity from dark to photoconditions.

It remains a great challenge to explore redox mediators with multi-electron, suitable redox potential, and stable pH buffer ability to simulate the natural solar-to-fuel process. In this work, we present a defect engineering strategy to design soluble multi-electron redox polyoxometalates mediators to construct a photocatalysis-electrolysis relay system to decouple H2 and O2 evolution in solar-driven water splitting. The appropriate use of vanadium atoms to replace tungsten in the Dawson-type phosphotungstate successfully regulated the redox properties of the molecular clusters. Specifically, the single vanadium substitution structure ({P2W17V}) possesses 1-electron redox active and sequential proton-electron transfer behavior, while the tri-vanadium substituted cluster ({P2W15V3}) exhibits 3-electron redox active and cooperative proton electron transfer behavior. Based on the developed multi-electronic redox mediator with pH buffering capacity, suitable redox potential (0.6 V), and fast electron exchange rate, we build a photocatalysis-electrolysis relay water splitting system. This system allows for high capacity of solar energy storage through photocatalytic O2 evolution using BiVO4 photocatalyst and stable H2 production with a high Faraday efficiency of over 98.5% in the electrolysis subsystem.

Although crystal facet engineering of semiconductor crystals has been demonstrated to be effective in particulate photocatalysts for solar energy conversion, it is imperative to rationally regulate the exposed crystal facets and their configurations to improve charge separation efficiency. In this study, focusing on visible-light-driven water oxidation photocatalyst lead chromate (PbCrO4), we find that a flux-assisted treatment enables the precise tuning of the hole-accumulating facets of anisotropic PbCrO4 crystal, transitioning the top surface from {-101} to {001} facets while preserving its spatial charge separation characteristics. Owing to the superior hole-accumulating property and water oxidation kinetics of the {001} facets, the resulting Flux-PbCrO4 crystals achieve a charge separation efficiency exceeding 75%, leading to a remarkable improvement in photocatalytic water oxidation activity. Further incorporation of cocatalysts onto the Flux-PbCrO4 crystals results in an apparent quantum efficiency of 18.5% at 500 nm for photocataly tic water oxidation.

The asymmetric addition of aromatic organometallic compounds to the carbonyl group (C-3) of isatins, catalyzed by transition metals, has emerged as a remarkably efficient method for the synthesis of chiral 3-hydroxyoxindoles. Here, an exceptionally enantioselective approach was developed for the first time to achieve a catalytic NHK reaction of isatins with aromatic halides (both aryl and heteroaryl). Utilizing chiral cobalt complexes as catalysts, and the presence of a diboron reagent B2nep2 as both a reducing agent and determinant in enantiocontrol, has resulted in the triumphantly achieved synthesis of enantioenriched products. Compared to reported strategies, this approach exhibits remarkable compatibility with substrates bearing sensitive functional groups, such as halides and borate esters, while also eliminating the need for organometallic reagents as required in previous strategies. Through experimental investigations, the presence of aryl-cobalt species during the addition process was confirmed, rather than in-situ generation of an arylboron reagent. Furthermore, the successful attainment of the R absolute configuration through aryl addition was demonstrated.

To fully harness the potential of surface plasmon resonance (SPR) in augmenting photocatalytic water oxidation, a comprehensive exploration of structure-activity relationship of metal nanoparticles is essential. This work presents a wrap-bake-peel (WBP) strategy designed to stabilize AuCu/TiO2 nanostructures while preserving SPR absorption and refining the metal-semiconductor interfaces. Through strategically incorporating trace Cu into Au (Cu/Au = 0.06), we achieved a 2.6-fold enhancement of SPR-induced oxygen evolution reaction (OER) performance compared to pristine Au/TiO2. This enhancement is due to the synergistic effect of SPR and a well-defined Schottky barrier, which improves plasmonic hot carrier charge separation, as verified by detailed spectroscopic analyses. The incorporation of copper plays a critical role, acting as an electron shuttle that facilitates the transfer of hot electrons from photoexcited gold to the AuCu NP surface, thereby reducing recombination. This process, driven by SPR-induced hot electrons from Au, also extends electron-phonon (tau(0)(e-ph)), interactions by 138 %, significantly prolonging hot carrier lifetimes. Mechanistic insights reveal that d-band onset potentials (Ed-AuCu similar to-0.9 V/ Ed-Au similar to-1.2 V) and increased hot hole d-band occupancy in AuCu further enhance the overall SPR-induced water oxidation performance. Simulated electron distributions and quantum confinement in AuCu vs. Au critically dictate SPR characteristics, enabling precise modulation of plasmonic responses. These findings underscore the crucial role of Cu in fine-tuning the properties of plasmonic photocatalysts, demonstrating a significant advancement in the rational design of efficient solar-to-fuel conversion systems.

A prevalent challenge in particulate photocatalytic water splitting lies in the fact that while numerous photocatalysts exhibit outstanding hydrogen evolution reaction (HER) activity in organic sacrificial reagents, their performance diminishes markedly in a Z-scheme water splitting system using electronic mediators. This underlying reason remains undefined, posing a long-standing issue in photocatalytic water splitting. Herein, we unveiled that the primary reason for the decreased HER activity in electronic mediators is due to the strong adsorption of shuttle ions on cocatalyst surfaces, which inhibits the initial proton reduction and results in a severe backward reaction of the oxidized shuttle ions. To address this, taking typical visible-light-responsive photocatalysts, BaTaO2N and SrTiO3:Rh, as examples, we have developed a strategy via selective surface modification of metal cocatalysts (such as Pt, Ru) with chromium oxide species (CrOx) to prevent the adsorption of shuttle ions. It is demonstrated that the photocatalytic HER activities of BaTaO2N and SrTiO3:Rh can be improved by one to two orders of magnitude in diverse shuttle ions. The introduced CrOx substantially weakens the interaction between the metal cocatalysts and shuttle ions, promotes proton adsorption for the HER reaction, and also suppresses the backward reaction between shuttle ions. Owing to the improved HER activity, the photocatalytic performance of Z-scheme water splitting is significantly enhanced, providing a feasible strategy for constructing efficient Z-scheme systems in heterogeneous photocatalysis.

Metallaaromatics are attractive due to their special structures and properties. In this work, the first metalla-phenalenyl complexes containing CReC units were obtained from ReCl3(PMePh2)3 and 1,8-diethynylnaphthalene compounds. The delocalized rhenaphenalenyl structure exhibits good planarity. DFT studies show that the 3MR rhenacyclopropene units are σ-aromatic, while the 6MR rhenacycle is nonaromatic. Though the rhenapolycycle is stable, it can be oxidized with one 3MR broken, resulting in another rhenaphenalenyl structure.

The photocatalytic oxidation of water with gaseous oxygen is environmentally benign for the synthesis of hydrogen peroxide (H2O2), but it is currently constrained by the inadequate supply of gaseous oxygen at the catalyst surface in a solid-liquid-gas triple-phase reaction system. Herein, we address this challenge by employing the zeolite encapsulated catalysts that efficiently enrich gaseous oxygen and accelerate the H2O2 synthesis in aqueous conditions. We focus on the classical titania photocatalyst, encapsulating it within siliceous MFI zeolite crystals. This encapsulation results in a significant enhancement in H2O2 synthesis efficiency, achieving a yield that is ten times greater than that with unencapsulated TiO2. Mechanism study reveals that gaseous oxygen is notably concentrated within the microporous structure of the zeolite under aqueous conditions, thereby facilitating its interaction with the titania surface at the liquid-solid interface. In addition, the H2O2 product could swiftly transfer through the micropores, thereby reducing the side reaction of decomposition. This design provides an alternative pathway to address the poor gas solubility of gaseous reactants in water, and paves the way for advancements in various other photocatalytic processes.

Laser-induced ripple structures formation at photoresist films (thickness of 700 nm) is investigated in water and in air using a partial polarized Excimer laser beam (wavelength of & lambda; = 248 nm, pulse duration of & tau; = 25 ns). Unlike the LIPSS (Laser-induced periodic surface structures) generated in air, the laser-induced corrugated ripples have a nondirectional structure. A minimal laser fluence of - 11 mJ/cm2 is required for the laser-induced ripples' formation in water which is two times higher than that of - 5 mJ/cm2 in air. The laser fluence required for the ripples' formation on the photoresist is decreasing with the increased laser pulse numbers that indicates the incubation effects. The height of the ripples increases with the applied laser pulse numbers. The maximal height of the ripples can reach to about 180 nm. The width of the ripples increases with the laser pulse numbers and saturates at about 450 nm. FIB (Focused ion beam) cross sections indicate that the ripples are still developed on the photoresist substrate, and the residual thickness of the substrate is about 500 nm. The bubbles generated by laser beam ablation change the laser bean path and then affect the laser transmission. The morphological characteristics of the corrugated structures suggest that the mechanisms are related to the hydrodynamic instabilities of the melted photoresist during the thermal process of laser irradiation, the bubbles' pulsation and the scattering of the fast moving small bubbles induced by the collapsing of big bubbles. This study may help to understand the mechanisms of laser fabrication under water confinement better and promote the potential applications in laser micromachining techniques.