S-Modified Graphitic Carbon Nitride with Double Defect Sites For Efficient Photocatalytic Hydrogen Evolution.

Graphitic carbon nitride (gC3N4) is an attractive photocatalyst for solar energy conversion due to its unique electronic structure and chemical stability. However, gC3N4 generally suffers from insufficient light absorption and rapid compounding of photogenerated charges. The introduction of defects and atomic doping can optimize the electronic structure of gC3N4 and improve the light absorption and carrier separation efficiency. Herein, the high efficiency of carbon nitride photocatalysis for hydrogen evolution in visible light is achieved by an S-modified double-deficient site strategy. Defect engineering forms abundant unsaturated sites and cyano (─C≡N), which promotes strong interlayer C─N bonding interactions and accelerates charge transport in gC3N4. S doping tunes the electronic structure of the semiconductors, and the formation of C─S─C bonds optimizes the electron-transfer paths of the C─N bonding, which enhances the absorption of visible light. Meanwhile,C≡N acts as an electron trap to capture photoexcited electrons, providing the active site for the reduction of H+ to hydrogen. The photocatalytic hydrogen evolution efficiency of SDCN (1613.5 µmol g-1 h-1) is 31.5 times higher than that of pristine MCN (51.2 µmol g-1 h-1). The charge separation situation and charge transfer mechanism of the photocatalysts are investigated in detail by a combination of experimental and theoretical calculations.

Strain Engineering of Cd0.5Zn0.5S Nanocrystal for Efficient Photocatalytic Hydrogen Evolution from Wasted Plastic.

The challenge of synthesizing nanocrystal photocatalysts with adjustable lattice strain for effective waste-to-energy conversion is addressed in this study. Cd0.5Zn0.5S (CZS) nanocrystals are synthesized by a simple solvothermal method, regulation of the ratio between N, N-dimethylformamide, and water solvent are shown to provoke expansion and contraction, inducing an adjustable lattice strain ranging from -1.2% to 5.6%. With the hydrolyzed wasted plastic as a sacrificial agent, the 5.6% lattice-strain CZS exhibited a robust hydrogen evolution activity of 1.09 mmol m-2 h-1 (13.83 mmol g-1 h-1), 4.5 times that of pristine CZS. Characterizations and density functional theory calculation demonstrated that lattice expansion increases the spatial distance between the valence band maximum and conduction band minimum, thus reducing carrier recombination and promoting charge transfer. Additionally, lattice expansion induces surface S vacancies and adsorbed OH groups, further enhancing redox reactions. This study focuses on the synchronous regulation of crystal structure, charge separation/transport, and surface reactions through lattice strain engineering, which providing a reference for the rational design of new photocatalysts for effective waste-to-energy conversion.

An All-In-One Integrating Strategy for Designing Platinum(II)-Based Supramolecular Polymers for Photocatalytic Hydrogen Evolution.

Organic polymer photocatalysts have achieved significant progress in photocatalytic hydrogen evolution, while developing the integrated organic polymers possessing the functions of photosensitizer, electron transfer mediator, and catalyst simultaneously is urgently needed and presents a great challenge. Considering that chalcogenoviologens are able to act as photosensitizers and electron-transfer mediators, a series of chalcogenoviologen-containing platinum(II)-based supramolecular polymers is designed, which exhibited strong visible light-absorbing ability and suitable bandgap for highly efficient photocatalytic hydrogen evolution without the use of a cocatalyst. The hydrogen evolution rate (HER) increases steadily with the decrease in an optical gap of the polymer. Among these "all-in-one" polymers, Se-containing 2D porous polymer exhibited the best photocatalytic performance with a HER of 3.09 mmol g-1 h-1 under visible light (>420 nm) irradiation. Experimental and theoretical calculations reveal that the distinct intramolecular charge transfer characteristics and heteroatom N in terpyridine unit promote charge separation and transfer within the molecules. This work could provide new insights into the design of metallo-supramolecular polymers with finely tuned components for photocatalytic hydrogen evolution from water.

Pt Single Atoms Loaded on Thin-Layer TiO2 Electrodes: Electrochemical and Photocatalytic Features.

Recently, the use of Pt in the form of single atoms (SA) has attracted considerable attention to promote the cathodic hydrogen production reaction from water in electrochemical or photocatalytic settings. First, produce suitable electrodes by Pt SA deposition on Direct current (DC)-sputter deposited titania (TiO2) layers on graphene-these electrodes allow to characterization of the electrochemical properties of Pt single atoms and their investigation in high-resolution HAADF-STEM. For Pt SAs loaded on TiO2, electrochemical H2 evolution shows only a very small overpotential. Concurrent with the onset of H2 evolution, agglomeration of the Pt SAs to clusters or nanoparticles (NPs) occurs. Potential cycling can be used to control SA agglomeration to variable-size NPs. The electrochemical activity of the electrode is directly related to the SA surface density (up to reaching the activity level of a plain Pt sheet). In contrast, for photocatalytic H2 generation already a minimum SA density is sufficient to reach control by photogenerated charge carriers. In electrochemical and photocatalytic approaches a typical TOF of ≈100-150 H2 molecules per second per site can be reached. Overall, the work illustrates a straightforward approach for reliable electrochemical and photoelectrochemical investigations of SAs and discusses the extraction of critical electrochemical factors of Pt SAs on titania electrodes.

MIL-125-PDI/ZnIn2S4 Inorganic-Organic S-Scheme Heterojunction With Hierarchical Hollow Nanodisc Structure for Efficient Hydrogen Evolution from Antibiotic Wastewater Remediation.

Efficient photocatalytic production of H2 from wastewater is expected to address environmental pollution and energy crises effectively. However, the rapid recombination of photoinduced carriers results in low photoconversion efficiency. At present, inorganic-organic S-scheme heterojunction have become a prominent and promising technology. In this study, an organic ligand modified MIL-125-PDI/ZnIn2S4 (ZIS) inorganic-organic S-scheme heterojunction catalyst is designed. ZIS nanosheets are grown on the disc-shaped MIL-125-PDI surface to form a distinctive hollow nanodiscs with hierarchical structure, giving the material an abundance of surface active sites, an optimized electronic structure, and a spatially separated redox surface. Consequently, the optimal 100MIL-125-PDI250/ZIS exhibited high photocatalytic HER of 508.99 µmol g-1 h-1 in Tetracycline hydrochloride (TC-HCl) solution. Meanwhile, the catalyst achieved complete TC-HCl removal and mineralization rate of 66.62% in 4 h. Experimental and theoretical calculations corroborate that the staggered band alignment and work function difference between MIL-125-PDI and ZIS induce the formation of a built-in electric field, thus regulating the charge transfer routes and consequently enhancing charge separation efficiency. The possible photocatalytic mechanism is analyzed using liquid chromatography-mass spectrometry (LC-MS), and the toxicities of the degradation products are also evaluated. This work presents a green dual-function strategy for H2 production and antibiotic wastewater recycling.

Facile Synthesis of Organic-Inorganic Hybrid Heterojunctions of Glycolated Conjugated Polymer-TiO2-X for Efficient Photocatalytic Hydrogen Evolution.

The utilization of the organic-inorganic hybrid photocatalysts for water splitting has gained significant attention due to their ability to combine the advantages of both materials and generate synergistic effects. However, they are still far from practical application due to the limited understanding of the interactions between these two components and the complexity of their preparation process. Herein, a facial approach by combining a glycolated conjugated polymer with a TiO2-X mesoporous sphere to prepare high-efficiency hybrid photocatalysts is presented. The functionalization of conjugated polymers with hydrophilic oligo (ethylene glycol) side chains can not only facilitate the dispersion of conjugated polymers in water but also promote the interaction with TiO2-X forming stable heterojunction nanoparticles. An apparent quantum yield of 53.3% at 365 nm and a hydrogen evolution rate of 35.7 mmol h-1 g-1 is achieved by the photocatalyst in the presence of Pt co-catalyst. Advanced photophysical studies based on femtosecond transient absorption spectroscopy and in situ, XPS analyses reveal the charge transfer mechanism at type II heterojunction interfaces. This work shows the promising prospect of glycolated polymers in the construction of hybrid heterojunctions for photocatalytic hydrogen production and offers a deep understanding of high photocatalytic performance by such heterojunction photocatalysts.

P-N Bonds-Mediated Atomic-Level Charge-Transfer Channel Fabricated between Violet Phosphorus and Carbon Nitride Favors Charge Separation and Water Splitting.

Heterostructures are widely employed in photocatalysis to promote charge separation and photocatalytic activity. However, their benefits are limited by the linkages and contact environment at the interface. Herein, violet phosphorus quantum dots (VPQDs) and graphitic carbon nitride (g-C3N4) are employed as model materials to form VPQDs/g-C3N4 heterostructures by a simple ultrasonic pulse excitation method. The heterostructure contains strong interfacial P-N bonds that mitigate interfacial charge-separation issues. P-P bond breakage occurs in the distinctive cage-like [P9] VPQD units during longitudinal disruption, thereby exposing numerous active P sites that bond with N atoms in g-C3N4 under ultrasonic pulse excitation. The atomic-level interfacial P-N bonds of the Z-scheme VPQDs/g-C3N4 heterostructure serve as photogenerated charge-transfer channels for improved electron-hole separation efficiency. This results in excellent photocatalytic performance with a hydrogen evolution rate of 7.70 mmol g-1 h-1 (over 9.2 and 8.5 times greater than those of pure g-C3N4 and VPQDs, respectively) and apparent quantum yield of 11.68% at 400 nm. Using atomic-level chemical bonds to promote interfacial charge separation in phosphorene heterostructures is a feasible and effective design strategy for photocatalytic water-splitting materials.

Tailoring Advanced CdS Anisotropy-Driven Charge Spatial Vectorial Separation and Migration via In Situ Dual Co-Catalyst Synergistic Layout.

Tailoring advanced anisotropy-driven efficient separation and migration of photogenerated carriers is a pivotal stride toward enhancing photocatalytic activity. Here, CdS-MoS2 binary photocatalysts are tailored into a dumbbell shape by leveraging the rod-shaped morphology of CdS and employing an in situ tip-induction strategy. To further enhance the photocatalytic activity, an in situ photo-deposition strategy is incorporated to cultivate MnOx particles on the dumbbell-shaped CdS-MoS2. The in situ deposition of MnOx effectively isolated the oxidatively active sites on the CdS surface, emphasizing the reductively active crystalline face of CdS, specifically the (002) face. Benefiting from its robust activity as a reduction active site, MoS2 adeptly captures photogenerated electrons, facilitating the reduction of H+ to produce hydrogen. The anisotropically driven separation of CdS photogenerated carriers markedly mitigates the Coulomb force or binding force of the photogenerated electrons, thus promoting a smoother migration toward the active site for photocatalytic hydrogen evolution. The hydrogen evolution rate of 35MnOx-CdS-MoS2-3 surpasses that of CdS by nearly an order of magnitude, achieving a quantum efficiency of 22.30% at 450 nm. Under simulated solar irradiation, it attains a rate of 42.86 mmol g-1 h-1. This work imparts valuable insights for the design of dual co-catalysts, anisotropy-driven spatial vectorial charge separation and migration, and the analysis of migration pathways of photogenerated carriers.

Direct Observation of Z-Scheme Route in Cu31S16/ZnxCd1-xS Heteronanoplates for Highly Efficient Photocatalytic Hydrogen Evolution.

Although photocatalytic hydrogen production from water holds great potential as a renewable and sustainable energy alternative, the practical application of the technology demands cost-effective, simple photocatalytic systems with high efficiency in hydrogen evolution reaction (HER). Herein, the synthesis and characterization of Cu31S16/ZnxCd1-xS heterostructured nanoplates (Cu31S16/ZnCdS HNPs) as a high photocatalytic system are reported. The cost-effective, hierarchical structures are easily prepared using the Cu31S16 NPs as the seed by the epitaxial growth of the ZnCdS nanocrystals (NCs). The Cu31S16/ZnCdS without the noble metal cocatalyst exhibits a high HER rate of 61.7 mmol g-1 h-1, which is 8,014 and 17 times higher than that of Cu31S16 and ZnCdS, respectively, under visible light irradiation. The apparent quantum yield (AQY) of Cu31S16/ZnCdS reaches 67.9% at 400 nm with the highest value so far in the reported ZnCdS-based photocatalysts. The excellent activity and stability of the Cu31S16/ZnCdS are attributed to the formation of a strong internal electric field (IEF) and the Z-scheme pathway. The comprehensive experiments and theoretical calculations provide the direct evidences of the Z-scheme route. This work may offer a way for the design and development of efficient photocatalysts to achieve solar-to-chemical energy conversion at a practically useful level.

Nanoarchitectonics toward Full Coverage of CdZnS Nanospheres by Layered Double Hydroxides for Enhanced Visible-Light-Driven H2 Evolution.

Nanoarchitectonics of semiconductors shed light on efficient photocatalytic hydrogen evolution by precisely controlling the surface microenvironment of cocatalysts. Taking cadmium zinc sulfide (CZS) nanoparticles as a target, the spontaneous modifications are conducted by interactions between surface Cd2+/Zn2+ atoms and thiol groups in thioglycolic acid. The capping ligand impacts the semiconductor surface with a negative electronic environment, contributing to the full coverage of CZS by nickel-cobalt hydroxides (NiCo-LDHs) cocatalysts. The obtained core-shell CZS@NiCo-LDHs, possessing a shell thickness of ≈20 nm, exhibits a distinguished topology (SBET = 87.65m2 g-1), long surface carrier lifetime, and efficient charge-hole separation. Further photocatalytic hydrogen evaluation demonstrates an enhanced H2 evolution rate of 18.75 mmol g-1 h-1 with an apparent quantum efficiency of 16.3% at 420 nm. The recorded catalytic performance of the core-shell sample is 44.6 times higher than that of pure CZS nanospheres under visible light irradiation. Further density functional theory simulations indicate that sulfur atoms play the role of charge acceptor and surface Ni/Co atoms are electron donors, as well as a built-in electric field effect can be established. Altogether, this work takes advantage of strong S affinity from surface metal atoms, revealing the interfacial engineering toward improved visible-light-driven photocatalytic hydrogen evolution (PHE) activity.

Performance and Solution Structures of Side-Chain-Bridged Oligo (Ethylene Glycol) Polymer Photocatalysts for Enhanced Hydrogen Evolution under Natural Light Illumination.

Converting solar energy into hydrogen energy using conjugated polymers (CP) is a promising solution to the energy crisis. Improving water solubility plays one of the critical factors in enhancing the hydrogen evolution rate (HER) of CP photocatalysts. In this study, a novel concept of incorporating hydrophilic side chains to connect the backbones of CPs to improve their HER is proposed. This concept is realized through the polymerization of carbazole units bridged with octane, ethylene glycol, and penta-(ethylene glycol) to form three new side-chain-braided (SCB) CPs: PCz2S-OCt, PCz2S-EG, and PCz2S-PEG. Verified through transient absorption spectra, the enhanced capability of PCz2S-PEG for ultrafast electron transfer and reduced recombination effects has been demonstrated. Small- and wide-angle X-ray scattering (SAXS/WAXS) analyses reveal that these three SCB-CPs form cross-linking networks with different mass fractal dimensions (f) in aqueous solution. With the lowest f value of 2.64 and improved water/polymer interfaces, PCz2S-PEG demonstrates the best HER, reaching up to 126.9 µmol h-1 in pure water-based photocatalytic solution. Moreover, PCz2S-PEG exhibits comparable performance in seawater-based photocatalytic solution under natural sunlight. In situ SAXS analysis further reveals nucleation-dominated generation of hydrogen nanoclusters with a size of ≈1.5 nm in the HER of PCz2S-PEG under light illumination.

2D Porphyrin-Based Covalent-Organic Framework/PEG Composites: A Rational Strategy for Photocatalytic Hydrogen Evolution.

Two-dimensional porphyrin-based covalent-organic frameworks (2D-por-COFs) have gained significant attention as attractive platforms for efficient solar light conversion into hydrogen production. Herein, it is found that introducing transition metal zinc and polyethylene glycol (PEG) into 2D-por-COFs can effectively improve the photocatalytic hydrogen evolution performance. The photocatalytic hydrogen evolution rate of ZnPor-COF is 2.82 times higher than that of H2Por-COF. Moreover, ZnPor-COF@PEG has the highest photocatalytic hydrogen evolution efficiency, which is 1.31 and 3.7 times that of pristine ZnPor-COF and H2Por-COF, respectively. The filling of PEG makes the layered structure of COFs more stable. PEG reduces the distortion and deformation of the carbon skeleton after the experiment of photocatalytic hydrogen evolution. The layered stacking and crystallization of 2D-por-COFs are also enhanced. Meanwhile, the presence of PEG also accelerates the transfer of excited electrons and enhances the photocatalytic hydrogen evolution activity. This strategy will provide valuable insights into the design of 2D-por-COFs as efficient solid photocatalysts for solar-driven hydrogen production.

Unlocking solar energy's potential: Dual photocatalytic activities of g-C3N4/Sb2S3 for hydrogen evolution and tetracycline degradation in sunlight.

This study focuses on developing a g-C3N4/Sb2S3 heterojunction photocatalyst with different g-C3N4 to Sb2S3 weight ratios (1:1, 1:3, and 3:1) for degrading tetracycline (TC) pollutants. The 1:3 ratio (13 GS) exhibited optimal photocatalytic performance, achieving 99% TC degradation under sunlight within 120 min, compared to 78.4% under visible light and 38% under UV light. The 13 GS catalyst demonstrated strong reusability, maintaining 80% degradation efficiency after six cycles. Scavenger experiments identified hydroxyl radicals as crucial for TC degradation, with DMSO reducing activity by 30%. The photocatalyst also showed high hydrogen production with an apparent quantum efficiency (AQE) of 19.8% under standard conditions, and improved AQE in acidic (23%) and basic (22.7%) conditions, and with CH3OH (23.2%). This g-C3N4/Sb2S3 heterojunction offers a promising solution for degrading toxic contaminants and has the potential for solar-powered applications.

Exploring Geometric Chirality in Nanocrystals for Boosting Solar-to-Hydrogen Conversion.

Advancing catalyst design is pivotal for the enhancement of photocatalytic processes in renewable energy conversion. The incorporation of structural chirality into conventional inorganic solar hydrogen nanocatalysts promises a significant transformation in catalysis, a feature absent in this field. Here we unveil the unexplored potential of geometric chirality by creating a chiral composite that integrates geometric chiral Au nanoparticles (NPs) with two-dimensional C3N4 nanosheets, significantly boosting photocatalytic H2 evolution beyond the achiral counterparts. The superior performance is driven by the geometric chirality of Au NPs, which facilitates efficient charge carrier separation through the favorable C3N4-chiral Au NP interface and chiral induced spin polarization, and exploits high-activity facets within the concave surfaces of chiral Au NPs. The resulting synergistic effect leads to a remarkable increase in photocatalytic H2 evolution, with an apparent quantum yield of 44.64 % at 400 nm. Furthermore, we explore the selective polarized photo-induced carrier separation behavior, revealing a distinct chiral-dependent photocatalytic HER performance. Our work advances the design and utilization of chiral inorganic nanostructures for superior performance in energy conversion processes.

Electrosynthesis of an Improbable Directly Bonded Phosphorene-Fullerene Heterodimensional Hybrid toward Boosted Photocatalytic Hydrogen Evolution.

Phosphorene and fullerene are representative two-dimensional (2D) and zero-dimensional (0D) nanomaterials respectively, constructing their heterodimensional hybrid not only complements their physiochemical properties but also extends their applications via synergistic interactions. This is however challenging because of their diversities in dimension and chemical reactivity, and theoretical studies predicted that it is improbable to directly bond C60 onto the surface of phosphorene due to their strong repulsion. Here, we develop a facile electrosynthesis method to synthesize the first phosphorene-fullerene hybrid featuring fullerene surface bonding via P-C bonds. Few-layer black phosphorus nanosheets (BPNSs) obtained from electrochemical exfoliation react with C60 2- dianion prepared by electroreduction of C60, fulfilling formation of the "improbable" phosphorene-fullerene hybrid (BPNS-s-C60). Theoretical results reveal that the energy barrier for formation of [BPNS-s-C60]2- intermediate is significantly decreased by 1.88 eV, followed by an oxidization reaction to generate neutral BPNS-s-C60 hybrid. Surface bonding of C60 molecules not only improves significantly the ambient stability of BPNSs, but also boosts dramatically the visible light and near-infrared (NIR) photocatalytic hydrogen evolution rates, reaching 1466 and 1039 µmol h-1 g-1 respectively, which are both the highest values among all reported BP-based metal-free photocatalysts.

Polyoxometalate-Based Single-Atom Catalyst with Precise Structure and Extremely Exposed Active Site for Efficient H2 Evolution.

Single-atom catalysts with precise structure and extremely high catalytic efficiency remain a fervent focus in the fields of materials chemistry and catalytic science. Herein, a nickel-substituted polyoxometalate (POM) {NiSb6O4(H2O)3[ß-Ni(hmta)SbW8O31]3}15- (NiPOM) with one extremely exposed nickel site [NiO3(H2O)3] was synthesized using the conventional aqueous method. The uniform dispersion of single nickel center with well-defined structure was facilely achieved by anchoring nanosized NiPOM on graphene oxide (GO). The resulting NiPOM/GO can couple with CdS photoabsorber for the construction of low-cost and ultra-efficient hydrogen evolution system. The H2 yield can reach to 2753.27 mmol gPOM -1 h-1, which represents a record value among all the POM-based photocatalytic systems. Remarkablely, an extremely high hydrogen yield of 3647.28 mmol gPOM -1 h-1 was achieved with simultaneous photooxidation of commercial waste plastic, representing the first POM-based photocatalytic system for H2 evolution and waste plastic conversion. This work highlights a straightforward strategy for constructing extremely exposed single-metal site with precise microenvironment by facilely manipulating nanosized molecular cluster to control individual atom.

Simultaneous Defect Passivation and Co-Catalyst Engineering Leads to Superior Photocatalytic Hydrogen Evolution on Metal Halide Perovskites.

Metal halide perovskites (MHPs) have emerged as attractive candidates for producing green hydrogen via photocatalytic pathway. However, the presence of abundant defects and absence of efficient hydrogen evolution reaction (HER) active sites on MHPs seriously limit the solar-to-chemical (STC) conversion efficiency. Herein, to address this issue, we present a bi-functionalization strategy through decorating MHPs with a molecular molybdenum-sulfur-containing co-catalyst precursor. By virtue of the strong chemical interaction between lead and sulfur and the good dispersion of the molecular co-catalyst precursor in the deposition solution, a uniform and intimate decoration of the MHPs surface with lead sulfide (PbS) and amorphous molybdenum sulfide (MoSx) co-catalysts is obtained simultaneously. We show that the PbS co-catalyst can effectively passivate the Pb-related defects on the MHPs surface, thus retarding the charge recombination and promoting the charge transfer efficiency significantly. The amorphous MoSx co-catalyst further promotes the extraction of photogenerated electrons from MHPs and facilitates the HER catalysis. Consequently, drastically enhanced photocatalytic HER activities are obtained on representative MHPs through the synergistic functionalization of PbS and MoSx co-catalysts. A solar-to-chemical (STC) conversion efficiency of ca. 4.63 % is achieved on the bi-functionalized FAPbBr3-xIx (FA=CH(NH2)2), which is among the highest values reported for MHPs.

Delocalizing Excitation for Highly-Active Organic Photovoltaic Catalysts.

Localized excitation in traditional organic photocatalysts typically prevents the generation and extraction of photo-induced free charge carriers, limiting their activity enhancement under illumination. Here, we enhance delocalized photoexcitation of small molecular photovoltaic catalysts by weakening their electron-phonon coupling via rational fluoro-substitution. The optimized 2FBP-4F catalyst we develop here exhibits a minimized Huang-Rhys factor of 0.35 in solution, high dielectric constant and strong crystallization in the solid state. As a result, the energy barrier for exciton dissociation is decreased, and more importantly, polarons are unusually observed in 2FBP-4F nanoparticles (NPs). With the increased hole transfer efficiency and prolonged charge carrier lifetime highly related to enhanced exciton delocalization, the PM6 : 2FBP-4F heterojunction NPs at varied concentration exhibit much higher optimized photocatalytic activity (207.6-561.8 mmol h-1 g-1) for hydrogen evolution than the control PM6 : BP-4F and PM6 : 2FBP-6F NPs, as well as other reported photocatalysts under simulated solar light (AM 1.5G, 100 mW cm-2).

Enhancing Built-in Electric Fields via Molecular Symmetry Modulation in Supramolecular Photocatalysts for Highly Efficient Photocatalytic Hydrogen Evolution.

Nature-inspired supramolecular self-assemblies are attractive photocatalysts, but their quantum yields are limited by poor charge separation and transportation. A promising strategy for efficient charge transfer is to enhance the built-in electric field by symmetry breaking. Herein, an unsymmetric protonation, N-heterocyclic π-conjugated anthrazoline-based supramolecular photocatalyst SA-DADK-H+ was developed. The unsymmetric protonation breaks the initial structural symmetry of DADK, resulting in ca. 50-fold increase in the molecular dipole, and facilitates efficient charge separation and transfer within SA-DADK-H+. The protonation process also creates numerous active sites for H2O adsorption, and serves as crucial proton relays, significantly improving the photocatalytic efficiency. Remarkably, SA-DADK-H+ exhibits an outstanding hydrogen evolution rate of 278.2 mmol g-1 h-1 and a remarkable apparent quantum efficiency of 25.1 % at 450 nm, placing it among the state-of-the-art performances in organic semiconductor photocatalysts. Furthermore, the versatility of the unsymmetric protonation approach has been successfully applied to four other photocatalysts, enhancing their photocatalytic performance by 39 to 533 times. These findings highlight the considerable potential of unsymmetric protonation induced symmetry breaking strategy in tailoring supramolecular photocatalysts for efficient solar-to-fuel production.

Transforming Red Phosphorus Photocatalysis: Dual Roles of Pre-Anchored Ru Single Atoms in Defect and Interface Engineering.

Crystalline red phosphorus (CRP), known for its promising photocatalytic properties, faces challenges in photocatalytic hydrogen evolution (PHE) due to undesired inherent charge deep trapping and recombination effects induced by defects. This study overcomes these limitations through an innovative strategy in integrating ruthenium single atoms (Ru1) within CRP to simultaneously repair the intrinsic undesired vacancy defects and serve as the uniformly distributed anchoring sites for a controllable growth into ruthenium nanoparticles (RuNP). Hence, a highly functionalized CRP with Ru1 and RuNP (Ru1-NP/CRP) with concerted effects in regulating electronic structures and promoting interfacial charge transfer has been achieved. Advanced characterizations unveil the pioneering dual role of pre-anchored Ru1 (analogous to the "Tai Chi" principle) in transforming CRP photocatalysis. The regulations of vacancy defects on the surface of CRP minimize the detrimental deep charge trapping, resulting in the prolonged lifetime of active charges. With the well-distributed in situ growth of RuNP on Ru1 sites, the constructed robust "bridge" that connects CRP and RuNP facilitates constructive interfacial charge transfer. Ultimately, the synergistic effect induced by the pre-anchored Ru1 endows Ru1-NP/CRP with an exceptional PHE rate of 3175 µmol h-1 g-1, positioning it as one of the most efficient elemental-based photocatalysts available. This breakthrough underscores the crucial role of pre-anchoring metal single atoms at defect sites of catalysts in enhancing sustainable hydrogen production.