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Ti-incorporated mesoporous materials have widespread applications in photocatalysis. Their adjustable pores could accommodate dyes like alizarin red S (ARS) to circumvent the lack of visible light response. Herein, Ti-MCM-41 was obtained to anchor visible light-capturing ARS, forming ARS-Ti-MCM-41. The ARS-Ti-MCM-41 was screened for the selective photocatalytic oxidation of organic sulfides. To improve the stability of the anchored ARS, electron transfer was orchestrated by a mediator trimethylamine (TMA, 2 mol%) illuminated by blue LEDs. Phenyl methyl sulfide could be almost entirely converted into phenyl methyl sulfoxide with 99% of selectivity within 18 min. In addition, Ti-MCM-41 was beneficial for the anchored ARS, which in turn guaranteed good recycling performance of ARS-Ti-MCM-41. The solvent trifluoroethanol enabled the stability of TMA and facilitated the highly selective formation of the target sulfoxides. This work sheds light on the vast possibility for visible light photocatalysis of dye-mesoporous materials.

One sustainable concept emerges to implement the selective oxidation of sulfides with dioxygen (O2) at ambient conditions and has received increasing attention. As such, three donor–acceptor (D–A) type conjugated microporous polymers (CMPs) were connected via robust C C bonds prepared from FeCl3-promoted polymerization of monomers of 3,6-di(9H-carbazol-9-yl)-9H-fluorene with the 9H position of the fluorene moiety occupied by 1,1′-biphenyl-, difluoro-, or keto- group, furnishing 9,9′-(9,9′-spirobi[fluorene]-2,7-diyl)-bis-9H-carbazole-CMP (SFC-CMP), 9,9′-(9,9-difluoro-9H-fluorene-2,7-diyl)bis(9H-carbazole)-CMP (FFC-CMP), and 2,7-di(carbazol-9-yl)-fluoren-9-one-CMP (OFC-CMP), respectively. These three carbazole–fluorene CMPs could implement blue light-driven highly selective oxidation of sulfides into sulfoxides with O2 in methanol (CH3OH). Intriguingly, the SFC-CMP imparted the best photocatalytic activity for selective oxidation of sulfides in a broad scope. Besides, the SFC-CMP photocatalyst could be fully recovered even outperforming the fresh one. This work highlights that the properties of CMPs could be regulated by the D–A units like carbazole–fluorene to execute selective chemical transformations ambiently.

The hollow core–shell structure ZnFe2O4@C in this work has excellent EM absorption performance.

Recently, conjugated microporous polymers (CMPs) comprised of thiazolo[5,4-d]thiazole (TzTz) linkages have received much attention due to their excellent photoelectric properties. Herein, the polycondensation of dithiooxamide and benzyl aldehydes of C2, C3, and D2h symmetry afforded three TzTz-linked CMPs, namely TzTz-CMP-1, TzTz-CMP-2, and TzTz-CMP-3. Importantly, the porous and flexible characteristics of TzTz-linked CMPs enable the smooth selective aerobic oxidation of amines in ethanol (C2H5OH), a clean but redox-active solvent. All three TzTz-linked CMPs significantly surpass the benchmark mesoporous graphite carbon nitride (mpg-C3N4) photocatalyst. Intriguingly, TzTz-CMP-2 displays the best photocatalytic activity for the blue-light-mediated selective transformation of primary and secondary amines into imines. The conversions of amines were up to 90% with excellent selectivities for imines. This work highlights that CMPs with TzTz linkages may offer efficient photocatalytic selective transformations under genuinely ambient conditions.

Pesticide carbaryl can cause serious environmental pollution and its sensitive detection is of increasing interest. Gold nanoparticles (AuNPs) are classically colorimetric probes for detection of many analytes, but the instability in complex media limits their application. Here, Au@Ova NPs have been developed as a stable, effective, sensitive, and selective sensing system for colorimetric detection of carbaryl. Au@Ova NPs present unique and proper colloidal stability in various medias containing salt, small molecules, organic solvent (DMSO), and seawater, which are distinct from previous ones including citrate (or rhodamine B) capped AuNPs. Compared with Au@BSA NPs, Au@Ova NPs showed efficient responses to carbaryl by inhibiting acetylcholinesterase, with a linear concentration range between 0 and 25 μg/L and a detection limit of 0.25 μg/L. In addition, this nanoprobe also has good selectivity and can be applied in different real samples analysis, including fruit juice (tomato and apple) and real water samples (artificial urine and seawater).

Nowadays, the application range of biomass materials was more and more extensive.In this work,peanut shell powder was used as the raw material. The nanocellulose is extracted from it by chemical mechanical method.Then, using the sol-gel method, methyltrimethoxysilane(MTMS) is added to the peanut shell nanocellulose suspension to modify it. Finally, the nano-cellulose superhydrophobic aerogel was prepared by freeze-drying method. The nano-cellulose aerogel and polydimethylsiloxane (PDMS) were finished on the cotton fabric by spraying method, and the superhydrophobic aerogel and superhydrophobic cotton fabric were analyzed and characterized respectively. The results show that the prepared nanocellulose aerogel has a three-dimensional sheet-like structure with superhydrophobicity. The hydrophobic properties and water contact angle (WCA) of cotton fabrics were significantly improved after superhydrophobic finishing. The WCA can reach 160.4°, the finished fabric has good antifouling performance and self-cleaning performance, and the oil-water separation efficiency reaches 82.2%.

Two-dimensional covalent organic frameworks (2D COFs) have received increasing attention in photocatalysis recently. Merging their photocatalytic process with an additional redox mediator could improve the corresponding chemical conversion efficiency, leading to an interesting cooperative behaviour. Herein, we report the photocatalytic performance of a 2D imine-linked porphyrin-based COF (Por-COF) with (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) in a selective organic transformation. After being irradiated with white light-emitting diodes, Por-COF showed moderate activity in selective aerobic oxidation of sulfides. Interestingly, by using TEMPO as an electron transfer mediator, the photocatalytic efficiency could be significantly improved, due to a paradigm of cooperative photocatalysis between Por-COF and TEMPO. This work foreshadows that 2D COFs can provide a unique platform to construct cooperative photocatalysts with a redox mediator.

Dye-semiconductor assemblies are very versatile visible light photocatalysts in terms of tunability by tweaking either dye molecules or semiconductor materials. Here, we adopted a strategy of molecular inverse design of alizarin red S (ARS) to identify the blueprint underlying the superior photocatalytic activity of ARS-TiO2 assembly. We discovered that the substituted -OH groups of anthraquinone provide visible light absorption and binding sites. Importantly, the molecular features of 1,2-dihydroxyanthraquinone (1,2-DHA) contributes mostly to the unique photocatalytic activity after binding with TiO2 with broad visible light absorption which can be maintained at high concentration of amines. Moreover, the electron-withdrawing effect of -SO3-Na+ groups increase the acidities of substituted -OH groups, leading to stronger binding and subsequent higher activity. Ultimately, in situ formed 1,2-DHA-TiO2 assembly can be a powerful photocatalyst for green light-induced selective oxidation of amines into imines with aerial O2. This work makes evident the promise of molecular design in tailoring dye-semiconductor assemblies for visible light-induced photocatalytic selective chemical transformations.

Nb2O5 is a colourless metal oxide that is very promising in areas such as energy storage and optical glasses. These applications depend on the superior redox properties of Nb2O5 compared to those of other metal oxides, which in turn endow it with great potential in semiconductor photocatalysis. Herein, a hierarchical Nb2O5 was synthesized by the L-arginine-assisted hydrothermal method. Thereafter, visible light photocatalysis was bridged over hierarchical Nb2O5 with a common organic dye, namely alizarin red S (ARS), significantly renovating Nb2O5-based photocatalysis from ultraviolet (UV) into the green light region. The surface of hierarchical Nb2O5 was chemically modified with ARS to harvest 520 nm green light and facilitate the oxidation of organic sulfides with aerial O2. The O-atom transfer from O2 into sulfoxides with very high selectivity occurs via an intermediate of superoxide radical anions (O2˙−). Importantly, the electron transfer from activated ARS to sulfides is mediated by an electron transfer mediator, namely (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO), to deter the attack of quenched ARS by reactive oxygen species (ROS). This study represents the first foray of dye-semiconductor assemblies based on a semiconductor other than TiO2 for the selective aerobic oxidation, affirming the generality of cooperative photocatalysis and implying the great potential of hierarchical Nb2O5 in platforming the visible-light-induced selective transformation of organic molecules.

In this work, Cu2ZnSn1-xGexS4 (CZTGS) precursor thin films with varied Ge composition (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) were prepared by using a water-based solution approach. After selenizing at 550 °C for 10 min in a graphite box containing selenium powder, the as-fabricated kesterite Cu2ZnSn1-xGex(S,Se)4 (CZTGSSe) thin films were systematically investigated for phase structure, morphology, valence states of elements, optical properties, and electrical properties. The results showed that the Ge element was successfully incorporated into the host lattice of Cu2ZnSn(S,Se)4 (CZTSSe), and kesterite CZTGSSe films were formed. As the Ge content increased, the crystal grains in the films grew larger and showed uniform morphology on the sample surfaces. The band gap in the CZTGS(Se) thin films could be engineered in the range of 1.21 eV–2.00 eV by tuning the relative compositions of the Ge elements. Furthermore, it was confirmed that the doping of Ge improved the mobility, resistivity, and photoelectric performance of the films. Finally, the Cu2ZnSn0.8Ge0.2(S,Se)4 solar cell device with an efficiency of 5.39% was prepared. The results indicate that non-toxic water solution-based CZTGSSe films showed potential for application in solar cells.

The selective aerobic oxidation of sulfides is highly attractive for modern organic and pharmaceutical synthesis. Thus, there is an urgent need for exploring new photocatalytic system on this reaction. In this work, we investigated the polyimide-titanium dioxide (Aeroxide P25 TiO2, denoted as P25) photocatalyst in visible light-driven selective aerobic oxidation of sulfides. Polyimide-P25 shows enhanced absorption of visible light. Subsequently, this makes polyimide-P25 exhibits observable photocatalytic activity on visible light-driven selective aerobic oxidation of sulfides while pure polyimide and P25 individually have none. Aided by triethylamine (TEA), the yield of sulfoxide by polyimide-P25 photocatalysis reaches more than 3 folds compared to that without TEA, highlighting the remarkable cooperative effect between polyimide-P25 photocatalysis and TEA catalysis. Moreover, a plausible mechanism is figured out based on the quenching control experiments, kinetic studies and in-situ electron paramagnetic resonance (EPR) tests. This work could provide useful guidance for the rational design of hybrid photocatalysts to undertake challenging selective chemical transformations.

2D covalent organic frameworks (COFs) are receiving ongoing attention in semiconductor photocatalysis. Herein, we present a photocatalytic selective chemical transformation by combining sp2 carbon-conjugated porphyrin-based covalent organic framework (Por-sp2 c-COF) photocatalysis with TEMPO catalysis illuminated by 623 nm red light-emitting diodes (LEDs). Highly selective conversion of amines into imines was swiftly afforded in minutes. Specifically, the π-conjugation of porphyrin linker leads to extensive absorption of red light; the sp2 -C=C- double bonds linkage ensures the stability of Por-sp2 c-COF under high concentrations of amine. Most importantly, we found that crystalline framework of Por-sp2 c-COF is pivotal for cooperative photocatalysis with (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO). This work foreshadows that the outstanding hallmarks of COFs, particularly crystallinity, could be exploited to address energy and environmental challenges by cooperative photocatalysis.

To solve the problems in online target detection on the embedded platform, such as high missed detection rate, low accuracy, and slow speed, a lightweight target recognition method of MobileNetv3-CenterNet is proposed. This method combined the anchor-free Centernet network with the MobileNetv3 small network and trained on the UA-DETRAC and PASCAL VOC07 + 12 standard datasets. While reducing the scale of the network model, the MobileNetv3-Centernet model shows a good balance in the accuracy and speed of target recognition and effectively solves the problem of missing detection of dense and small targets in online detection. To verify the recognition performance of the model, it is tested on 2683 images of the UA- DETRAC and PASCAL VOC 2007 datasets, and compared with the analysis results of CenterNet-DLA34, CenterNet-ResNet18, CenterNet-MobileNetv3-large, YOLOv3, MobileNetv2-YOLOv3, SSD, MobileNetv2-SSD and Faster R-CNN models. The results show that the MobileNetv3-CenterNet model accurately recognized the dense targets and small targets missed by other methods, and obtains a recognition accuracy of 99.4% with a running speed of FPS53. The comprehensive detection effect of MobileNetv3-CenterNet is better than other methods. The MobileNetv3-CenterNet lightweight target recognition method will provide effective technical support for the target recognition of deep learning networks in embedded platforms and online detection.

In order to better meet the communication needs of the hearing impaired and the general public, it is of great significance to recognize sign language more quickly and accurately in the embedded platforms and mobile terminals. A sign language recognition method based on the ShuffleNetv2-YOLOv3 lightweight model was proposed. By Using ShuffleNetv2 as the backbone network of the YOLOv3 model, the ShuffleNetv2-YOLOv3 method improved the recognition speed by the lightweight network with the CIoU loss function and more less detection layers; kept the recognition accuracy of similar gestures that were difficult to accurately recognize. Statistical analysis of the self-made sign language images was carried out to evaluate the recognition effectiveness of the model by F1 score and mAP value, and to compare it with YOLOv3-tiny, SSD, Faster-RCNN, MobileNetv2-YOLOv3, and YOLOv4-tiny models, respectively. The experimental results show that the proposed ShuffleNetv2-YOLOv3 model achieved a good balance between the accuracy and speed of gesture detection under the premise of model lightweight. The F1 score and mAP value of the ShuffleNetv2-YOLOv3 model were 99.1% and 98.4%, respectively, and the target detection speed on the GPU can reach 54 frames per second, which is better than other models. The ShuffleNetv2-YOLOv3 sign language recognition method is conducive to quick, real-time, and similar static sign language gesture recognition, which lays a good foundation for real-time dynamic gesture recognition.

Numerous applications in visible light photocatalysis have been found over conjugated microporous polymers (CMPs) whose function could be rationally designed at the molecular level. In this context, the oxidation of thiols into disulfides entails proton and electron transfer and thus requires both Brønsted base and photocatalysis, which could be both combined into CMPs. With carbazole as a Brønsted base and an electron donor, CMPs were constructed to implement the synergistic deprotonation and oxidation of thiols into disulfides in ethanol (C

Perfluorinated compounds (PFCs) are useful man-made chemicals and serve as new emerging organic pollutants due to their environmental and health concerns. Chromatography-mass detection methods often need complex procedure and are also too expensive, so there is a critical demand to develop rapid, inexpensive, easy-to-operate and sensitive methods for PFCs detection. In this work, double fluorescent biosensors ('DT sensor' and 'FT sensor') have been designed to quantitatively detect long-chain perfluorinated compounds (PFCs), due to their strong hydrophobic interaction with DNA probe or lysozyme fiber. The ratio and rapid fluorescence responses offered more obvious signal changes, and high sensitivity with a limit of detection (LOD) of 0.16 μM (98.2 ppb) for perfluorododecanoic acid (PFDoA). For three PFCs with longer perfluoroalkyl chain (CF

Steel fiber reinforced concrete (SFRC) is an appropriate material for protective structure and may undergo fire, impact and the coupled effects of them. To investigate the dynamic failure behavior of SFRC after elevated temperature, a mesoscale simulation method was established. In the approach, the SFRC was regarded as a four-phase composite material consisting of aggregate particles, mortar matrix and the interfacial transition zones between them as well as fibers. Each phase has its own independent thermal and mechanical properties. During the simulations, a sequentially coupled thermal-stress procedure was employed. In detail, thermal conduction within SFRC specimens was conducted firstly. Then, taking the results of damage and temperature field as the initial state, the dynamic failure behavior of SFRC under uniaxial compression was modelled. Comparison between simulation results and experimental observations reveals the rationality and accuracy of the simulation method. Based on the calibrated simulation approach, the mechanical performances of SFRC under various temperature and strain rates were simulated. Both the temperature degradation and strain rate enhancement effects on the apparent property of SFRC were studied. The results indicate that steel fiber can effectively improve the dynamic mechanical properties of concrete after high temperature and more adequately prevent crack evolution under high strain rate. The fiber enhancement effect on strength is weakened with the increase of strain rate, while that is more significant with the increase of temperature.

A general visible light photocatalytic protocol for the synthesis of imines via a two-step one-pot route on alizarin red S (ARS)-sensitized TiO2 was uncovered. This efficient synthesis protocol involves one step of the highly selective formation of aldehydes from the oxidation of alcohols with O2 on ARS-sensitized TiO2 photocatalyst, and a subsequent step of condensation of newly formed aldehydes with various amines on TiO2 to afford imines in one pot. Anatase TiO2 provides a versatile platform for catalytic amounts of ARS (0.67 mol%) to facilitate the electron transfer from dye traversing its conduction band to O2 under green LED irradiation. Moreover, the Lewis acid sites of TiO2 can promote the formation of imines from aldehydes and amines in very high isolated yields. We took advantage of both the photocatalytic and catalytic properties of TiO2 to significantly expand the scope of imines. Our work suggests that the synthetic applications of TiO2 photocatalysis can be achievable under mild conditions by exploring the excellent functionalities of TiO2.

TiO2 is the most established semiconductor photocatalyst. The prominence of TiO2 is becoming increasingly obvious because its interfacial redox reactions have implication on a wide range processes such as energy conversion and environmental remediation. Herein, we exploited the surface complex created by the interaction between organic molecules with binding sites and accommodating surface of TiO2 for visible light-driven selective aerobic oxidation reactions. A novel surface complex formed between N-hydroxyphthalimide (NHPI) and TiO2 was discovered. The NHPI-TiO2 complex turned out to be an outstanding visible light photocatalyst and was successfully used in the selective oxidation of amines into imines with atmosphere O2 under blue LED irradiation. The stability of the NHPI-TiO2 complex was preserved by 3 mol% of (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) acting as a cooperative catalyst. Moreover, selectivities for the imine products were also promoted by TEMPO. Superoxide anion radical (O2 −) were evidenced to be the primary reactive oxygen species (ROS) to execute the oxidative conversions. This work suggests that TiO2 surface complexes can be robust photocatalysts for visible light-driven selective aerobic reactions, provided that an appropriate cooperative redox catalyst exists to channel the photocatalytic electron transfer.

The interplay of salicylic acid (SA) and reactive oxygen species (ROS) can modulate biotic and abiotic stress of plants, essential biological aerobic oxidation processes. Meanwhile, ROS plays a critical role in TiO2 photocatalytic system for the degradation of organic species. Herein, we developed a system consisted of SA and TiO2 aiming at the selective oxidation of organic molecules by ROS. Interestingly, SA complexed with TiO2 leads to ligand-to-metal charge transfer (LMCT) under visible light irradiation. The charge transfer from ligand (chemically adsorbed SA) to metal (conduction band of TiO2) activates O2 to ROS, superoxide (O2 −). The positive charge located at ligand SA is connected with (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) catalysis for direct two-electron oxidation of amines and later regenerated by O2 −. SA and its derivatives were screened as ligands of TiO2 for the selective aerobic oxidation of amines into imines under blue light-emitting diode (LED) irradiation in which 5-CH3O-SA (5-methoxysalicylic acid, 0.8 mol%) complexed with anatase TiO2 and coupled with TEMPO (5 mol%) confers significantly better results than the others. By this visible light LMCT route, both primary amines and secondary amines can be selectively oxidized into corresponding imines with atmosphere O2 as the terminal oxidant. Importantly, the desired product of N-benzylidenebenzylamine can be isolated in 92% yield.

Cu–Bi co-doped ZnO nanospheres were obtained by adopting Bi and Cu to dope ZnO to improve their photocatalytic performance in the visible region. Cu–Bi co-doped ZnO nanospheres were successfully grown on the surface of cotton fabric by a sol–gel assisted hydrothermal method with citric acid as a morphology control agent. The obtained products were characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance spectroscopy (DRS). The results showed that the size of ZnO nanospheres was about 200 nm and doping with Cu and Bi did not change their morphology. Cu–Bi co-doped ZnO nanospheres presented a hexagonal wurtzite structure with high crystallinity; meanwhile, their band gap was also obviously reduced due to doping, from 3.24 eV to 2.82 eV. Cu–Bi co-doped ZnO nanospheres endowed the cotton fabric with excellent UV (ultraviolet) resistance with a UPF (Ultraviolet Protection Factor) value of 283.54 after 40 washes. Cotton fabric with 3% Bi–5% Cu co-doped ZnO on the surface showed 98.66% degradation of methylene blue (MB) solution under visible light irradiation for 150 min, indicating remarkable photocatalytic performance.

Carbaryl is a widely-used carbamate pesticide and the detection of its residues in environmental, food and clinical samples is of great importance. In this sturdy, we developed a green photocatalytic-biosensor based on double strand DNA-SYBR green I complex for sensitively colorimetric detection of carbaryl. This green photocatalytic-biosensor can oxidize 3,3',5,5'-tetramethylbenzidine (TMB) into blue ox-TMB. Meanwhile thiocholine is catalytically produced by acetylcholinesterase (AChE) to directly reduce blue ox-TMB into colorless TMB. But the activity of AChE will be suppressed by carbaryl, thus generating less thiocholine and resulting in more ox-TMB for colorimetric analysis. After the careful optimization of sensing conditions (2 μM for DNA concentration, 50 × concentration for SYBR Green I, 10 min for illumination time), the lowest detectable concentration for carbaryl is 0.008 ng/mL with a linear response in the range of 0.01-0.25 ng/mL. In addition, this photocatalytic-biosensor has good selectivity over non-target chemicals (acetamiprid, atrazine, carbendazim, melamine, bisphenol A, estradiol). It also allows detection of pesticides in real samples verified by a standard HPLC method.

Semiconductor photocatalysis can carry out selective chemical transformations under ambient conditions, mitigating the associated environmental consequences. However, a single semiconductor photocatalyst usually cannot perform the transformations satisfactorily from the aspects of light-absorption, efficiency, and selectivity, etc. To address these challenges, cadmium sulfide (CdS)/titanate hybrid was fabricated by simultaneously growing titanate and CdS and had been comprehensively characterized. The optimized CdS/titanate hybrid can power the highly selective oxidative homocoupling of amines under the irradiation of green light-emitting diodes (LEDs). Specifically, CdS with a narrow bandgap captures green light; the conduction band of titanate activates molecular oxygen (O2). The valence band of CdS could ensure the selective oxidative homocoupling of amines in methanol (CH3OH). The hybridization between CdS and titanate accounts for the expeditious oxidative homocoupling of amines into imines and the improved stability. Reactive oxygen species (ROS) quenching experiments and in situ electron paramagnetic resonance (EPR) tests suggest that superoxide anion (O2 −) and benzylamine radical are intermediates en route to imines. This work highlights the viability of hybridization of dual semiconductor nanostructures in implementing visible light-powered selective conversions.

TiO

Organic transformations face tremendous challenges in order to circumvent the necessity of poisonous reagents and harsh reaction conditions. These can, in principle, be addressed by photocatalysis that can turn them into environmentally friendly alternatives. In particular, visible-light photocatalytic selective oxidation of alcohols is posed to be one of the most common organic transformations, but a hugely formidable one. In view of this, we exploited a cooperative photocatalytic system to realize the efficient selective oxidation of alcohols with molecular oxygen (O2). A halogen-free organic dye, 5(6)-carboxyfluorescein [5(6)-FAM], was selected to anchor onto TiO2 with 4-methoxy-2,2,6,6-tetramethylpiperidine1-oxyl (CH3O-TEMPO) as a cocatalyst. A series of control experiments, involving TEMPO and its derivatives, different solvents, initial alcohol concentrations, different light-emitting diodes (LEDs), and TiO2, were carried out to optimize the results of alcohol oxidation. Importantly, reactive oxygen species (ROS) quenching experiments, spectroscopic analyses (such as electron paramagnetic resonance (EPR) and UV-visible absorption spectra), and kinetic studies provide evidence to a plausible mechanism for the cooperative photocatalytic reaction. Our work suggests that 5(6)-FAM-sensitized TiO2 can be applied as an efficacious photocatalyst and CH3O-TEMPO is more effective as compared to TEMPO. This discovery may open up a new path to visible-light photocatalytic selective organic transformations under ambient conditions.

Strong interfacial charge-transfer (ICT) has been observed between phenol and TiO2. It was demonstrated that a single Ph–O–Ti linkage could induce ICT transitions in the visible light region. By utilizing the surface complexation of phenol with TiO2, we, herein, present a new photocatalytic protocol for the selective oxidation of amines to imines in air. Our success depended on merging the phenol–TiO2 complex photocatalyst with (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO), so called cooperative photocatalysis, which improved stability of the surface-complexed phenol under the oxidative circumstance and promoted the selective conversion of amines. With 5 mol% of TEMPO as a co-catalyst and phenol–TiO2 complex (containing 0.8 mol% of phenol) as a photocatalyst, amines could be efficiently oxidized into imines with atmospheric O2 under blue light-emitting diode (LED) irradiation. In addition, a mechanism is proposed to explain the visible-light photocatalytic performance of the present system.