Strategy For Fabrication Research Articles

3D Nanofabrication via Directed Material Assembly: Mechanism, Method, and Future.

Fabrication of complex three-dimensional (3D) structures at nanoscale is the core of nanotechnology, as it enables the creation of various micro-/nano-devices such as micro-robots, metamaterials, sensors, photonic devices, etc. Among most 3D nanofabrication strategies, the guided material assembly, an efficient bottom-up approach capable of directly constructing designed structures from precise integration of material building blocks, possesses compelling advantages in diverse material compatibility, sufficient driving forces, facile processing steps, and nanoscale resolution. In this review, we focus on assembly-based fabrication methods capable of creating complex 3D nanostructures (instead of periodic or 2.5D-only structures). Recent advances are classified based on the different assembly mechanisms, i.e., assembly driven by chemical reactions, physical interactions, and the synergy of multiple microscopic interactions. The design principles of representative fabrication strategies with an emphasis on their respective advantages, e.g., structural design flexibility, material compatibility, resolution, or applications are analyzed. In the summary and outlook, existing challenges, as well as possible paths to solutions for future development are reviewed. We believe that with recent advances in assembly-based nanofabrication strategies, 3D nanofabrication has achieved tremendous progress in resolution, material generality, and manufacturing cost, for it to make a greater impact in the near future.

Enhanced degradation of tetracycline using ferrihydrite-decorated g-C3N4 via photocatalytic activation of peroxymonosulfate

While antibiotics benefit human health, their misuse and improper disposal harm ecosystems and human health. Thus, a novel Fh/N-g-C3N4 composite photocatalyst was prepared by in situ growing of ferrihydrite (Fh) nanoparticles on the surface of nitrogen-doped g-C3N4 (NCN) for the activation of peroxymonosulfate (PMS), to efficiently photo-degrade tetracycline. In this composite, the separation and transfer efficiency of photo-generated electron-hole pairs were significantly improved, while their recombination was effectively inhibited. The performance of the Fh/NCN-PMS system in degrading tetracycline under visible light demonstrated that 20%Fh/NCN composite photocatalyst, when coupled with PMS at a concentration of 200 mg/L, resulted in a degradation efficiency of 96.9 % for tetracycline at a concentration of 20 mg/L within 30 min. Mechanism investigation revealed that 4 main active species (SO4−, O2−, 1O2 and h+) were involved in tetracycline degradation, with 1O2 and h+ playing a predominant role. Moreover, the Fh/NCN composite demonstrated superior and consistent catalytic performance in activating PMS within a pH range of 4.5 to 10. Notably, the tetracycline degradation efficiency diminished by merely 7.1 % after four cycles of use. This study introduces a new strategy for fabrication of novel photocatalytic-PMS system, providing an efficient and highly stable treatment solution for antibiotic wastewater.

Surface Involvement in the Boosting of Chiral Organocatalysts for Efficient Asymmetric Catalysis

AbstractNanostructures with curved surfaces and chiral‐directing residues are highly desirable in the synthesis of asymmetric chemicals, but they remain challenging to synthesize without using unique templates due to the disfavored torsion energy of twisted architectures toward chiral centers. Here, a strategy for the facile fabrication of highly cured capsule‐shaped catalysts with chiral interiors by the amplification of molecular chirality via the irreversible cross‐linking of 2D asymmetric laminates is presented. The key to the success of these irregular 2D layers is the use of hierarchical assembly of chiral macrocycles, which can exactly regulate the cured nanostructures as well as asymmetric catalysis. The cross‐linking of 2D laminates from the assembly of hexameric macrocycles with one proline edge gave rise to rarely curled capsules with a diameter of 200–400 nm and excellent enantioselectivities as well as diastereoselectivities for asymmetric aldol reactions (94% ee and 1:13 dr). The tetrameric macrocycles decorated with the chiral block produced further curled porous structures, giving an outstanding enantioselectivities (up to 98% ee and 1:17 dr). The strategy of mechanical surface folding will provide a new insight related to increasing the enantioselectivity of chiral organocatalysts.

Self-Healing Supramolecular Flexible Network of Zn(II): Exploring Chemo-Responsiveness, Antimicrobial Efficiency, and Variable Microelectronic Device Performances.

The Zn(II)-supramolecular metallogel (i.e., Zn-Py) of 2,6-pyridinedicarboxylic acid was prepared through the addition of a metal source and 2,6-pyridinedicarboxylic acid as a low molecular weight gelator. The Zn-Py metallogel encapsulated N,N'-dimethylformamide as gel-immobilized polar aprotic solvent media. The mechanical features of the synthesized metallogel were investigated. The thixotropic behavior of the Zn-Py metallogel was also analyzed. The microscopic feature of the metallogel was imaged through FESEM and TEM studies. The EDS pattern of the metallogel ratified the role of different gel-building chemical constituents. The stimuli responsiveness of the metallogel was also tested. The metallogel-forming mechanistic protocol was visualized through FTIR and ESI mass spectroscopic analyses. The bioeffectiveness, i.e., antimicrobial potency, of Zn-Py was also studied. The antimicrobial efficiency against both Gram +ve and Gram -ve bacteria including Salmonella typhimurium (MTCC 98), Escherichia coli (MTCC 1667), Bacillus cereus (ATCC 13061), Listeria monocytogenes (MTCC 657), and Staphylococcus aureus (MTCC 96) was critically analyzed. The FESEM images of the live bacteria and damaged bacteria due to the action of the metallogel were experimentally investigated. The Zn-Py metallogel was also used to fabricate the heterojunction and Schottky-type photodetectors to show their excellent light-matter interaction and their potentiality as active material in optoelectronics. The electrical parameters of semiconductor diodes such as the p-n junction and Schottky diode fabricated by the synthesized Zn-Py metallogel were investigated. Outcomes of the experimental investigation demonstrated that the tested metallogel effectively showed p-n junction diode parameters, especially with the ideality factor (η) of 1.3 under a dark environment. This fabricated device efficiently depicted a great ON/OFF ratio of 33.4 at a reverse bias voltage of -2 V. The metal-semiconductor-metal (M-S-M) junction-type Schottky barrier diode was also fabricated using the Zn-Py metallogel where the Au/Zn-Py metallogel/Au-based device fabrication strategy was implemented.

A new critical growth parameter of H2/CH4 gas flow ratio and mechanistic model for SiC nanowire synthesis via Si substrate carbonization

SiC structures, including nanowires and films, can be effectively grown on Si substrates through carbonization. However, growth parameters other than temperature, which influence the preferential formation of SiC nanowires or films, have not yet been identified. In this work, we investigate SiC synthesis via Si carbonization using methane (CH4) by varying the growth temperature and the hydrogen to methane gas flow ratio (H2/CH4). We demonstrate that adjusting these parameters allows for the preferential growth of SiC nanowires or films. Specifically, SiC nanowires are preferentially grown when the H2/CH4 ratio exceeds a specific threshold, which varies with the growth temperature, ranging between 1200 and 1310 °C. Establishing this precise growth window for SiC nanowires in terms of the H2/CH4 ratio and growth temperature provides new insights into the parameter-driven morphology of SiC. Furthermore, we propose a mechanistic model to explain the preferential growth of either SiC nanowires or films, based on the kinetics of gas-phase reactions and surface processes. These findings not only advance our understanding of SiC growth mechanisms but also pave the way for optimized fabrication strategies for SiC-based nanostructures.

Poly(vinyl alcohol)-Assisted Exfoliation and Grafting Modification of Boron Nitride Nanosheets with a High Aspect Ratio via a Continuous Production Method for Energy Storage and Thermal Management.

Hexagonal boron nitride nanosheets (BNNS) integrating many extraordinary properties are usually combined with polymers to fabricate multifunctional dielectric materials for energy storage and thermal management. Unfortunately, the existing technologies for producing BNNS generally have the disadvantages of inefficiency and low product quality, which significantly hinder the wide application of high-value nanocomposites. Herein, a novel poly(vinyl alcohol) (PVA)-assisted pan-milling method based on the innovative solid-state shear milling (S3 M) technology is reported for the production of high-quality BNNS. The uniform three-dimensional (3D) shear force field generated by pan milling not only ensured the high aspect ratio of BNNS (the average lateral size of ∼954 nm and the average thickness of ∼3.7 nm) but also induced the mechanochemical reaction between PVA and BNNS to achieve in situ grafting modification on the BNNS surface. The simultaneous high-quality exfoliation and surface modification of BNNS positively contributed to the mechanical, dielectric, and thermal conduction properties of BNNS/PVA nanocomposites. At the BNNS content of 10 wt %, the BNNS/PVA composite film exhibited excellent robustness (Young's modulus of 5305 MPa and the tensile strength of 83 MPa), with a satisfactory breakdown strength (Eb of 134.7 MV/m) and dielectric constant (∼5 at 1000 Hz). In addition, the substantial improvement of thermal conductivity (from 0.88 to 5.59 W·m-1·K-1) guaranteed the stability of the dielectric properties of the nanocomposites at high temperatures. This pan-milling method characterized by green and efficiency is highly scalable to other two-dimensional (2D) layered materials, providing a practical strategy for the industrial fabrication of nanocomposites in elevated-temperature energy storage.

Scalable fabrication of freely shapable 3D hierarchical Cu-doped hydroxyapatite scaffolds via rapid gelation for enhanced bone repair

Critical-sized bone defects present a formidable challenge in tissue engineering, necessitating innovative approaches that integrate osteogenesis and angiogenesis for effective repair. Inspired by the hierarchical porous structure of natural bone, this study introduces a novel method for the scalable production of ultra-long, copper-doped hydroxyapatite (Cu-HAp) fibers, utilizing the rapid gelation properties of guar gum (GG) under controlled conditions. These fibers serve as foundational units to fabricate three-dimensional porous scaffolds with a biomimetic hierarchical architecture. The scaffolds exhibit a broad pore size distribution (1–500 μm) and abundant nanoporous features, mimicking the native bone extracellular matrix. Physicochemical characterization and in vitro assays demonstrated that the copper doping significantly enhanced osteogenic and angiogenic activities, with optimized concentrations (0.8 % and 1.2 % Cu) facilitating the upregulation of osteogenesis-related genes and proteins, as well as promoting endothelial cell proliferation. In vivo studies further confirmed the scaffolds' efficacy, with the 1.2Cu-HAp group showing a remarkable increase in bone regeneration (bone volume/total volume ratio: 35.7 ± 1.87 %) within the defect site. This research offers a promising strategy for the rapid fabrication of multifunctional scaffolds that not only support bone tissue repair but also actively accelerate the healing process through enhanced vascularization.

Characterization of the Phononic Landscape of Natural Nacre from Abalone Shells.

Natural design and fabrication strategies have long served as a source of inspiration for novel materials with enhanced properties. Less investigated is the prospect of leveraging the complexity of readily available, naturally occurring micro-/nanostructures as platforms for investigating functional materials. In the field of phononics, exploiting structural biocomposites is gaining traction; but finding natural phononic structures that interact with ultra- and hypersonic acoustic waves remains an open quest. In this context, the phononic behavior of natural Nacre, a biocomposite often looked at for inspiration due to its superlattice-like architecture of alternating organic and inorganic phases, is here characterized. To such end, a combination of non-contact pump-probe laser ultrasonics techniques and Brillouin spectroscopy are employed to interrogate Nacre's hierarchical structure at the micro- and nanoscale and measure its phononic dispersion behavior in the MHz and GHz range. It is found that for wavelengths longer than the brick-and-mortar characteristic length, Nacre behaves as a dispersionless medium with effective transversely isotropic properties; but as the wavelengths become comparable to its structural periodicity an involved phononic spectrum arises which challenges the notion of a perfectly periodic, high mechanical-contrast biocomposite.

Development of highly sensitive and stable patterned PDMS flexible strain sensors for motion monitoring via laser direct writing

Flexible strain sensors have received widespread attention for their potential applications in wearables, human–computer interaction, and healthcare. However, achieving a good balance between sensitivity, stretchability, and stability remains challenging. Here, we report a cost-effective and scalable fabrication strategy that combines laser direct writing (LDW) with 3D printing (3DP) to prepare various patterned Polydimethylsiloxane (P-PDMS) flexible strain sensors. By varying the laser parameters and processing paths, different microstructured patterns can be obtained, which significantly influence the sensor’s performance. By introducing patterned composite microstructures, the sensitivity of the strain sensor was increased by 339 % compared to the sensor without surface structures. Additionally, the strain sensors exhibit high stability and durability, a fast response time (140 ms), low hysteresis (0.009), and an ultra-low detection limit (0.0125 % strain). Besides, the sensors demonstrate excellent electrical performance and thermal stability. Based on their superior performance, we demonstrated their capability for real-time monitoring of human physiological signals. These findings successfully illustrate the potential of laser processing in fabricating complex microstructures, enabling the development of high-sensitivity flexible strain sensors for applications such as wearable health monitoring and human–computer interaction.

A simple way to make elastically-isotropic closed-cell plate-lattices: Effective properties of Ti-6Al-4V cubic+octet foam material

Architected metamaterials with optimal mechanical isotropy have been a long quest in the lightweight materials industry. Plate-lattices are likely to be the most promising candidates to fulfill this request. Nonetheless, unlocking full application potential of plate-lattices requires addressing many inherent drawbacks of existing additive manufacturing techniques. Hereby an alternative route is proposed to fabricate a particular plate-lattice, i.e., cubic+octet foam, based on snap-fit design concept. The proposed protocol allows for high-precision manufacturing, and is capable of scalable production with ease and offers great versatility in base material selection. Mechanical properties of plate-lattices created in this way are first numerically assessed, showing optimal stiffness and strength close to theoretical bounds for isotropic porous media, and a high degree of mechanical isotropy. Compression experiments are further conducted to exam the actual behavior of Ti-6Al-4V foam representatives, and compared with explicit simulations featuring fracture and interfacial-debonding processes, such that the dependency of foam’s performance on the degree of joint robustness is numerically quantified. Speaking of the uniqueness of this fabrication strategy, it allows for easy implementation of structural hierarchy and hybrid design; it also provides a simple way to utilize lab-scale advanced materials that are demanding even impractical to realize scalable production.

Magnetic coconut shell biochar/sodium alginate composite aerogel beads for efficient removal of methylene blue from wastewater: Synthesis, characterization, and mechanism

The challenges of recovering powdered biochar and its limited adsorption capacity are major obstacles to the application of agricultural waste in dye adsorption. To address these issues, this work fabricates Fe3O4-modified coconut shells biochar (mCSB)/sodium alginate (SA) aerogel beads using an in-situ crosslinking-gelation method and freeze-drying technology for methylene blue (MB) removal from wastewater. The spherical mCSB/SA aerogel beads with good magnetic properties (12.8 emu·g−1) can be easily separated from aqueous solutions, thereby completely avoiding the hazard of secondary pollution and device obstruction associated with powdered adsorbents. The absorption capability of MB by mCSB/SA aerogel beads was analyzed and optimized at different conditions. Furthermore, the maximum adsorption capacity of mCSB/SA aerogel beads is 625 mg·g−1 for MB, following the Langmuir isotherm model (R2 = 0.9997). Additionally, the adsorption process of MB on mCSB/SA aerogel beads is found to be spontaneous and endothermic, following the pseudo-second-order kinetic (R2 = 0.9991). Encouragingly, the adsorption efficiency of mCSB/SA aerogel beads remains above 95 % even after 5 times of reusability cycles, demonstrating excellent regeneration ability. This work proposes a straightforward and scalable fabrication strategy to convert agricultural waste into efficient adsorbents for wastewater treatment, adhering to the principles of sustainable development.

Preprocessed Monomer Interfacial Polymerization for Scalable Fabrication of High-Valent Cluster-Based Metal-Organic Framework Membranes.

Current research on emergent membrane materials with ordered and stable nanoporous structures often overlooks the vital facet of manufacturing scalability. We propose the preprocessed monomer interfacial polymerization (PMIP) strategy for the scalable fabrication of high-valent cluster-based metal-organic framework (MOF) membranes with robust structures. Using a roll-to-roll device on commercial polymer supports, Zr-fum-MOF membranes are continuously processed at room temperature through the PMIP approach. These large-area membranes demonstrate the preeminent hydrogen separation capabilities, boasting an order of magnitude of permeance and a thrice-enhanced selectivity when juxtaposed with conventional polymeric membranes. The obtained PMIP-Zr-fum-MOF membranes possess superior stability in water compared with interfacial polymerization (IP)-processed low-valent metal-ion-based ZIF-8 membranes. Moreover, we have implemented the PMIP strategy's universality to process the other four diverse MOF membranes. The proposal of PMIP significantly advances the scalable fabrication of water-stable high-valent cluster MOF membranes.

Microfluidic Bubble-Templating Multinozzle 3D Printing for Preparations of Macroporous Hydrogels with Ordered Pores of Large Size Ranges.

A strategy for fabrication of macroporous hydrogels through 3D printing assisted by molding and multiple microfluidic bubble-templating nozzles is proposed here. This approach aims to address the challenges faced by methods for 3D printing macroporous hydrogels, such as difficulties in precisely controlling the spatial distribution of macropores, limited porosity, and low resolution of external boundaries due to the poor mechanical properties of hydrogel solutions as printing ink. In this method, fast-switching microfluidic bubble-templating nozzles of varying sizes allowed for precise control of target pore sizes over a wide range. Cavities of polydimethylsiloxane (PDMS) molds were used to define the overall external shape of the hydrogels and enhance the resolution of the boundaries. During the printing process, the laminar shear force generated by a coaxial microfluidic system generated microbubbles which were then injected into the PDMS mold cavities. The spatial distribution of the microbubble clusters within the cavities was controlled by a 3D motion module. Finally, macroporous hydrogels with a pore size range of 238-930 μm were fabricated while avoiding millimeter round corners on the boundaries. A control precision of pore sizes was about 60 μm. Most importantly, this strategy broke through the space occupancy limitations of pores in traditional 3D printing methods for macroporous hydrogels. The space occupancy of pores could reach a maximum of about 87% within a single layer.

Synergistic effects of NiPtCo/Ti0.7W0.3O2 hybrid electrocatalysts for accelerating formic acid electro-oxidation performance.

We herein report the fabrication strategy of a robust catalyst for the formic acid electro-oxidation reaction (FAOR) via combining the advantages of a TiO2-related support and the synergistic effects of NiPtCo alloy. With the predominant dehydrogenation pathway, the NiPtCo/Ti0.7W0.3O2 catalyst shows remarkable FAOR mass activity and specific activity of 0.45 A mgMetal-1 and 1.25 mA cm-2, being 3.75- and 4.81-time higher than those of the commercially available Pt/C, respectively. The as-made FAOR electrocatalyst shows superior CO-tolerance and electrocatalytic stability during long-term operation conditions due to the synergistic contributions of each component in the overall catalyst system.

Advanced Preparation Methods and Biomedical Applications of Single-Atom Nanozymes.

Metal nanoparticles with inherent defects can harness biomolecules to catalyze reactions within living organisms, thereby accelerating the advancement of multifunctional diagnostic and therapeutic technologies. In the quest for superior catalytic efficiency and selectivity, atomically dispersed single-atom nanozymes (SANzymes) have garnered significant interest recently. This review concentrates on the development of SANzymes, addressing potential challenges such as fabrication strategies, surface engineering, and structural characteristics. Notably, we elucidate the catalytic mechanisms behind some key reactions to facilitate the biomedical application of SANzymes. The diverse biomedical uses of SANzymes including in cancer therapy, wound disinfection, biosensing, and oxidative stress cytoprotection are comprehensively summarized, revealing the link between material structure and catalytic performance. Lastly, we explore the future prospects of SANzymes in biomedical fields.

Partial Selenization Strategy for Fabrication of Ni0.85Se@NiCr-LDH Heterostructure as an Efficient Bifunctional Electrocatalyst for Overall Water Splitting.

NiCr-LDH and its partial selenization as Ni0.85Se@NiCr-LDH heterostructure is established here as an alkaline water electrolyzer for achieving enhanced overall water splitting efficiency. The hydrothermally synthesized optimized batch of Ni0.85Se@NiCr-LDH is thoroughly characterized to elucidate its structure, morphology, and composition. Compared to pristine NiCr-LDH, the batch of Ni0.85Se@NiCr-LDH exhibits exceptional alkaline OER and HER activity with low overpotentials of 258 and 85 mV at 10 mA cm-2, respectively. Besides, Ni0.85Se@NiCr-LDH also exhibits excellent acidic HER with an overpotential of only 61 mV at 10 mA cm-2, indicating that Ni0.85Se@NiCr-LDH can operate effectively across a wide pH range. The excellent electrochemical stability of Ni0.85Se@NiCr-LDH for 24 h operation is attributed to the formation of a thin layer of SeOx during OER operation. The role of selenization and the effect of Cr in the LDH lattice toward enhanced electrocatalytic water splitting is discussed. The outstanding OER and HER performances of Ni0.85Se@NiCr-LDH are attributed to the higher electrochemical active surface area, favorable conditions for adsorption of HER/OER intermediates, low charge transfer resistance, and improved conductivity. The practical application ofNi0.85Se@NiCr-LDHas a bifunctionalelectrocatalyst for overall water splitting is reflected from the low cell voltage of 1.548 V at 10 mA cm-2.

Strong, healable materials with bio‐like ordered architectures and versatile functionality

AbstractThe capacity of biological tissues to undergo self‐healing is crucial for the performance of functions and the continuation of life. Conventional intrinsic self‐healing materials demonstrate analogous functionality depending on the dissociation‐recombination of reversible bonds with no need of extra repair agents. However, the trade‐off relationship between mechanical strength and self‐healing kinetics in intrinsic self‐healing systems, coupled with the lack of additional functionality, restricts their service life and practical applications. Diversified highly ordered structures in organisms significantly affect the energy dissipation mechanism, signal transmission efficiency, and molecular network reconstruction capability due to their multi‐dimensional differentiated macroscopic composite constructions, microscopic orientation textures, and topologies/bonding types at molecular level. These architectures exhibit distinctive strengthening mechanisms and functionalities, which provide valuable references. This review aims at providing the current status of advanced intrinsic self‐healing materials with biomimetic highly ordered internal micro/nanostructures. Through highlighting specific examples, the classifications, design inspirations, and fabrication strategies of these newly developed materials based on integrating dynamic interactions with ordered nano/microstructures are outlined. Furthermore, the strengthening and self‐healing balance mechanisms, structure–functionalization relationships, and potential application values are discussed. The review concludes with a perspective on the challenges, opportunities, and prospects for the development, application, and promotion of self‐healable materials with bio‐like ordered architectures.

Highly Efficient Flexible Antimony Halide Scintillator Films with In Situ Preparation for High‐Resolution X‐Ray Imaging

AbstractFlexible scintillators with high light yield, spatial resolution and low light scattering are ideal for X‐ray imaging application. However, conventional scintillators are always prepared by crystallization of functional layer, grinding and mixing with polymers, resulting in serious light scattering. Herein, an in situ fabrication strategy is proposed to prepare a low light scattering flexible scintillator film based on 0D antimony halide C38H36P2SbCl5 (MTP2SbCl5). The prepared scintillator film exhibits bright yellow emission with an outstanding photoluminescence quantum yield (PLQY) of 99.69%, and it demonstrates linear responsiveness to X‐ray dose, achieving an impressive light yield of 39800 photons MeV−1 and a low detection limitation of 78.4 nGyair s−1. The scintillator film possesses strong radiation hardness and stability. In addition, low light scattering greatly inhibits optical crosstalk during X‐ray detection, effectively improving the spatial resolution of MTP2SbCl5 film from 4.5 to 10.2 lp mm−1. On account of the simple preparation method and high performance, this work provides guidance for the preparation of high‐efficiency, large‐area, low‐scattering and high‐resolution flexible scintillator in the future.

Visible-Light-Driven Oxidation of Benzene to Phenol with O2 over Photoinduced Oxygen-Vacancy-Rich WO3.

Direct photocatalytic conversion of benzene to phenol with molecular oxygen (O2) is a green alternative to the traditional synthesis. The key is to find an effective photocatalyst to do the trick. Defect engineering of semiconductors with oxygen vacancies (OVs) is an emerging strategy for catalyst fabrication. OVs can trap electrons to promote charge separation and serving as adsorption sites for O2 activation. However, the randomly distribution of OVs on the semiconductor surface often results in mismatching the charge carrier dynamics under irradiation, thus failing to fulfill the unique advantages of OVs for photoredox functions. Herein, we demonstrate that abundant OVs can be facilely generated and precisely located adjacent to the reductive sites on reducible oxide semiconductors such as tungsten oxide (WO3) via a simple photochemistry strategy. Such photoinduced OVs are well suited for photocatalytic benzene oxidation with O2 as they readily capture photogenerated electrons from the reductive sites of WO3 to activate adsorbed O2. The oxygen-isotope-labeling experiments further confirm that the OVs also facilitate the integration of oxygen atoms from O2 into phenol, revealing in detail the pathway for photocatalytic benzene hydroxylation. This study demonstrates that the photochemistry approach is an appealing strategy for the synthesis of high-performance OVs-rich photocatalysts for solar-induced chemical conversion.

Visible‐Light‐Driven Oxidation of Benzene to Phenol with O2 over Photoinduced Oxygen‐Vacancy‐Rich WO3

AbstractDirect photocatalytic conversion of benzene to phenol with molecular oxygen (O2) is a green alternative to the traditional synthesis. The key is to find an effective photocatalyst to do the trick. Defect engineering of semiconductors with oxygen vacancies (OVs) is an emerging strategy for catalyst fabrication. OVs can trap electrons to promote charge separation and serving as adsorption sites for O2 activation. However, the randomly distribution of OVs on the semiconductor surface often results in mismatching the charge carrier dynamics under irradiation, thus failing to fulfill the unique advantages of OVs for photoredox functions. Herein, we demonstrate that abundant OVs can be facilely generated and precisely located adjacent to the reductive sites on reducible oxide semiconductors such as tungsten oxide (WO3) via a simple photochemistry strategy. Such photoinduced OVs are well suited for photocatalytic benzene oxidation with O2 as they readily capture photogenerated electrons from the reductive sites of WO3 to activate adsorbed O2. The oxygen‐isotope‐labeling experiments further confirm that the OVs also facilitate the integration of oxygen atoms from O2 into phenol, revealing in detail the pathway for photocatalytic benzene hydroxylation. This study demonstrates that the photochemistry approach is an appealing strategy for the synthesis of high‐performance OVs‐rich photocatalysts for solar‐induced chemical conversion.