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Achieving large luminescence dissymmetry factors (glum) is challenging in the research field of circularly polarized luminescence (CPL). While various approaches have been developed to construct organic systems with CPL activity, there is still a lack of effective methods for fabricating CPL active inorganic materials. Herein, we propose an approach for endowing upconversion nanoparticles (UCNPs) and perovskite nanocrystal (PKNC) hybrid nanomaterials with upconverted circularly polarized luminescence (UC-CPL) activity. Chiral cesium lead bromides (CsPbBr3) PKNCs were synthesized by a chiral-ligand-assistant method. Meanwhile, UCNP could be embedded into the chiral PKNC, enabling a photon upconvesion feature to the PKNC. The embedded UCNPs in PKNCs were confirmed by electron tomography. Consequently, various CPL activities, including prompt CPL, UC-CPL, and energy transfer enhanced circularly polarized luminescence (ET-CPL), were realized. The chiral perovskite nanocrystals could reabsorb the chiral energy generated from UCNPs, showing energy transfer enhanced CPL activity with four times magnification of the circular polarization. These findings provide a meaningful strategy for designing chiral photon upconversion inorganic nanomaterials with highly efficient UC-CPL activity.

Novel flower-like Bi5O7I/Bi4Ti3O12 (BOI/BTO) photocatalysts were successfully designed and fabricated by an in situ growth method. The BOI and BTO in BOI/BTO composites have abundant interface contact and constructed a Z-scheme heterojunction structure. Therefore, these composites exhibited excellent performance for the selective oxidation of benzylic alcohols under visible light. It was attributed to the stronger absorption capacity of visible light and the high separation efficiency of photogenerated carriers via the Z-scheme transfer mechanism; especially, the sample BOI/BTO-1.5 achieved 92.4% selectivity for the oxidation of 4-methylbenzyl alcohol (4-MBA) to 4-methyl-benzaldehyde (4-MBAD) in the presence of H2O2, which also exhibited good stability, reusability and substrate adaptability. As evidenced by the activity experiments, trapping experiments and ESR analysis, the ˙O2− radicals and HOO˙ radicals were supposed to be the main active species directly involved in the photocatalytic oxidation process. Based on the optical and electrical analysis, a Z-scheme transfer facilitated mechanism of photocatalytic selective oxidation of benzylic alcohols was speculated.

The chirality of inorganic semiconductor nanocrystals (NCs) was demonstrated to be sensitive to the particle structures and chiral molecules capped on the NC surfaces. In this work, we found the native achiral ligands used for the synthesis of NCs could also influence their circular dichroism (CD) response. With different native ‘growth’ ligands but similar semiconductor cores, the CD spectra of NCs exhibited mirror images by using the same enantiopure cysteine (Cys) ligands, indicating the inversion of NC chirality. In addition, distinct anisotropic dissymmetry factors (g-factor) were observed. With appropriate native ligands, we prepared chiral cysteine stabilized spherical CdSe NCs (quantum dots, QDs) with the highest g-factor ever reported.

Stretchable conductors are important ingredients in the new emerging wearable systems. Here, intrinsically stretchable con­ductors (ISCs) based on carbon nanomaterials with a good balance of proper...

Copper sulfide (Cu2−xS) is a kind of cation deficient transition metal sulfide, which has attracted great interest due to its unique properties that arise from degenerate vacancy-doping, particularly its tunable localized surface plasmon resonance (LSPR) properties. In this work, a range of vacancy-doped Cu2−xS nanocrystals (NCs) (Cu1.2S, Cu1.4S, Cu1.75S, and Cu1.94S NCs) with a size of around 10 nm was prepared with tunable LSPR through a hot injection method. The doping level was manipulated effectively by varying the injection volume of sulfur powder–oleic acid (S–OA) to finely tune the LSPR wavelength. Cu2−xS NCs with four different doping levels were investigated as photocatalysts for degradation of dyes. The Cu1.94S NCs with the highest LSPR energy exhibited the best photocatalytic activity due to the highest free carrier density, presumably influenced by Cu vacancies and the volume of the S–OA solution. Theoretical calculations of the free carrier density of Cu2−xS NCs are consistent with the order of the photocatalytic activity. The results demonstrate that the correlation of the photocatalytic activity with the corresponding concentration of free holes and the LSPR wavelength is of interest, which will provide inspiration for the design of non-noble metal catalysts by regulating the free hole concentration in degenerate p-doped Cu2−xS caused by cation vacancies.

In this study, a biomimetic method assisted by bacitracin was applied to prepare spherical BiVO4 nanoparticles. The obtained BiVO4 nanoparticles were extensively characterized by XRD, SEM, TEM, BET, XPS, TGA, FTIR, UV-vis, PL, EIS and photocurrent density tests. The results indicated that bacitracin played a vital role in the induction and assembly of spherical BiVO4 nanoparticles. At the proper calcination temperature, C doping was achieved in the process of calcining biological templates. Moreover, the spherical BiVO4 nanoparticles were investigated as photocatalysts for the degradation of tetracycline hydrochloride (TH) under visible light. The spherical BiVO4 nanoparticles prepared with the present biological template by calcination at 300 °C exhibited the most excellent photocatalytic performance, and 98% TH could be degraded within 60 min under visible light. Compared with other samples, the T-300 sample has a larger exposed reaction surface, narrower band gap and more suitable C content, which all lead to improvement in the photocatalytic activity.

New ordered architectures or morphologies could be obtained through the self-assembly process and usually generate new physical and chemical properties. Here we report an adjustable self-assembly research study on copper sulphide nanocrystals (Cu1.94S NCs) forming five kinds of plant-like morphologies. Hydrophobic Cu1.94S quantum dots were prepared in the CHCl3 phase and transferred to the aqueous phase and capped with cysteine or penicillamine through a ligand exchange technique. Afterwards, a facile and eco-friendly self-assembly process (without using any template or surfactant) was employed. Through regulating the conditions including the solvent composition, surface ligand and starting concentration of Cu1.94S NCs, five delicate architectures were obtained. In addition, the possible formation process and growth mechanism of the obtained three-dimensional (3D) Cu1.94S architectures was also proposed and discussed. The assembled Cu1.94S architectures show improved molar extinction coefficients compared with individual Cu1.94S NCs, and in this way, better photothermal performance is achieved.

Different fusiform-shaped MIL-88A materials were successfully prepared by adjusting the mole ratio of the central metal ion and the organic ligand and using different polar solvents. With differently shaped MIL-88A supports, several Ag/AgCl@MIL-88A (ACML) were prepared successfully using the in situ growth method. These ACML composites showed a good photocatalytic activity under the simulated sunlight and visible light. The employment of Cl− ions, anchored on the surface of MIL-88A, could improve the dispersion and stability of the loaded Ag/AgCl nanoparticles. The s-ACML composite showed excellent photocatalytic stability during the cycle tests. The in situ growth strategy provided a facile method to design and synthesize MOF composite photocatalysts for wastewater treatment. In addition, based on the related optical and electrical characterization analysis, a possible mechanism of the ACML composite photocatalytic activity was proposed.

Graphitic carbon nitride (g-C3N4) has attracted enormous attention in photocatalysis owing to its special structure and properties. The insufficient light absorption and fast charge-carrier recombination limit its further photocatalytic application. Herein, we report a facile approach to fabrication of the g-C3N4 modified simultaneously with phosphorus and proton by directly heating the mixture of urea phosphate (UP) and urea in air. The incorporation of the phosphorus atoms in g-C3N4 can significantly decrease the band gap, leading to the enhanced light absorption efficiency. Furthermore, UP can also introduce the protons to the structure of g-C3N4 from protonation. The protons can inhibit the recombination of the charge carriers and improve their utilization. The synergistic effect of the phosphorus doping and protonation in g-C3N4 results in the superior visible-light photocatalytic performance for both degradation of Rhodamine B (RhB) and H2 evolution from water splitting. We believe that our findings...

An ingenious method was employed to design and fabricate the TiO2/g-C3N4 heterojunction photocatalysts in this study. The thermal oxidation etching of g-C3N4 nanosheets and the in situ growth of TiO2 nanocrystal on the surface of g-C3N4 nanosheets were completed simultaneously by the calcination process. The g-C3N4 nanosheets played a crucial role in regulating and assembling the structures and morphologies of TiO2. Furthermore, the thickness and content of g-C3N4, and the crystallinity of TiO2 in TiO2/g-C3N4 composites could be regulated and controlled by the calcination temperature. Among the resultant TiO2/g-C3N4 samples, the TiO2/g-C3N4 sample with 41.6 wt% g-C3N4 exhibited the highest photocatalytic activity. It could degrade almost all MO molecules under visible light irradiation within 3 h. Moreover, it displayed higher visible light photocatalytic performance for degrading MO solution than pure g-C3N4 and D-TiO2. The synergistic effect between TiO2 and g-C3N4 makes significant contributions to the enhancement of the visible light photocatalytic activity. In addition, the favorable photocatalytic performance of TiO2/g-C3N4 nanocomposites is also attributed to the porous structures and uniform morphologies, and large surface area. Furthermore, the resultant TiO2/g-C3N4 exhibits excellent photocatalytic stability. Radical trapping experiments indicated that O2− and h+ were the main reactive species during the photodegradation process under visible light irradiation. Hopefully, the results can offer new design and strategy for preparing other g-C3N4-based nanocomposites for environmental and energy applications.

Tubular structure TiO2/C/TiO2 hybrids were successfully fabricated via impregnation-calcination method. A castoff of tubular structure FCT (the fluff of the chinar tree) was employed as template and carbon source, and economical TiCl4 was purchased as titanium source. In particular, the outer tube wall of the TiO2/C/TiO2 hybrid was constructed with interlaced and curly nanofibers. Nevertheless, the inner tube wall was assembled with spheroid-likely TiO2 nanoparticles. In addition, the graphitic carbon layer was formed between TiO2 nanofibers and nanoparticles. The FCT played a vital role in inducing and assembling the hierarchical tube structure of the TiO2/C/TiO2 hybrid. Furthermore, the design of the hydrolysis reaction during the preparation process also made contributions on building the unique structure. The hydrolysis reaction was taken place by blowing atmosphere, which could control the hydrolysis reaction at an appropriate reaction rate. Furthermore, the graphitic C layer in the TiO2/C/TiO2 hybrid could accelerate the migration and separation of the photogenerated electron during the reaction process. At appropriate carbon content, the TiO2/C/TiO2 could degrade 99% tetracycline hydrochloride (TH) under simulated sunlight irradiation within 30 min.

Coupling the heterojunction system with surface plasmon resonance (SPR) effect is an innovative and feasible strategy to improve photocatalyst. An excellent Z-scheme CdSe-Ag-WO3-Ag photocatalyst was constructed via continuous photo-assisted process, which exhibited superior photocatalytic activity in H2 evolution (448.31 μmol•g−1 for 4 h) with simultaneous degradation of CFZ (96.32% in just 30 min) compared with CdSe-WO3, CdSe and WO3. This developed system conforms to Z-scheme electron transfer mode: CB/WO3 to Ag NPs, Ag NPs to VB/CdSe. It was verified by experiments, DFT simulation and in situ XPS characterization. So the strong reducing electron in CB/CdSe and the strong oxidizing hole in VB/WO3 were retained for H2 evolution and degradation, respectively. The coupling Ag with Z-scheme heterojunction can realize rapid electron transfer and utilization. Because the Z-scheme heterojunction inhibits recombination of carriers of the single catalyst itself and enhances electrons life, Ag acts as conductive channel to accelerate electrons transfer, and the surface defects of CdSe and Schottky barrier reduce the energy loss during the electron transmission process. This work provides new insights for boosts electron transfer to improve photocatalytic performance.

Hierarchical micro/nanostructured tubular TiO 2 were prepared by impregnation-calcination method with FCT (the fluff of the chinar tree) as biological template and titanium tetrachloride as precursor. The resultant samples possess curly tubular structure and the exterior outline of the samples look like fried dough twist. Moreover, the wall of the tube is assembled with spherical-likely nanoparticles. Apparently in the process of preparation, the FCT played pivotal roles as substrate and inducer for assembling the curly tubular structure of micro/nanostructured TiO 2 . Furthermore, the micro/nanostructured TiO 2 have abundant pore structures and large surface area, which are beneficial to the improvement of photocatalytic activity. Under UV light irradiation, the as-prepared TiO 2 exhibits nearly 100% photocatalytic decolorization rate in 30 min and 90% TOC (total organic carbon) degradation rate in 60 min for dye methyl orange (MO).

In this study, hierarchical micro/nanostructured tubular TiO2 photocatalysts were fabricated with the fluff of the chinar tree (FCT) as a biological template and titanium tetrachloride (TiCl4) as a precursor through an impregnation–calcination method. The structure, morphology and optical properties were extensively characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption–desorption, Fourier-transform infrared spectroscopy (FTIR), UV-vis diffused reflectance spectroscopy (UV-vis) and photoluminescence (PL) spectra. The results indicated that the FCT played pivotal roles as a template and inducer to assemble the tubular micro/nanostructure. Interestingly, the morphologies and structures of the outer tube wall of the obtained materials could be controlled and tailored by adjusting the dosages of TiCl4. In addition, the structures of the outer tube wall of the samples could be tuned from cross-linked nanobelts to interlaced nanofibers, and then spherical-likely nanoparticles by adjusting the dosages of TiCl4. Moreover, the as-prepared TiO2 material exhibited a 99.8% photocatalytic degradation rate for 15 mg L−1 rhodamine B (RhB) in 30 min under a 300 W mercury lamp. Compared with P25, the obtained TiO2 had superior photocatalytic activity. Furthermore, the hierarchical micro/nanostructured tubular TiO2 was easily recycled and had excellent photocatalytic stability.

The effect ofα-substitute groups at the asymmetric carbon of chiral monocarboxylic acid ligand, on the chirality of CdSe nanocrystals (NCs) was studied. When the substitution groups have strong electron-withdrawing capability, the CdSe NCs displayed an enhanced chirality where theg-factors were comparable to those with dicarboxylic chiral ligands. In addition, adding ethanol was demonstrated as an effective way to stabilize NCs, however, completely oppositeg-factor evolution behavior was found for NCs with differentα-substituted ligands. Specifically, theg-factor has increased/decreased with strong/weak electron-withdrawingα-substitute groups probably due to the different intermolecular hydrogen bonding between carboxylic acids and ethanol.

Hierarchical tubular micro-nano structured AgCl/Ag/TiO2 hybrids were successfully prepared via impregnation-hydrolyzation-calcination method combining with photo-reduction method. And the fluff of chinar tree (denoted as FCT) was employed as template; TiCl4 and AgNO3 were used as titanium and chlorine source, and Ag source, respectively. The characterization results showed that the as-prepared AgCl/Ag/TiO2 hybrid possessed hierarchical tube structure and the template of FCT was crucial in inducing and assembling the unique structure of AgCl/Ag/TiO2. The dosage of AgNO3 also had significant influence on the morphology and structure of the resultant sample. The catalytic activity of AgCl/Ag/TiO2 was affected by the mass ratio of AgCl, Ag and TiO2 in hybrids. At the appropriate mass ratio of AgCl, Ag and TiO2, the resultant sample could degrade 96% tetracycline hydrochloride (TH, 10 mg L−1) after visible light irradiation 3 h. It also exhibited well stable photocatalytic activity under visible light after four cycles. The favorable activity and stability should be due to the surface plasmon resonance (SPR) effects of Ag substance and the intimate connection among Ag, AgCl and TiO2 in AgCl/Ag/TiO2. It could broaden the range of light absorption and accelerate the charge migration. The results of the trapping experiments indicated that the •O2− radicals are the vital active species of oxidation during the photocatalytic degradation process.

A facile and economical method assisted by PPs (the spongy white peels of pomelo peel) was applied for preparing interlaced mesh structures TiO 2 nanofibers by a liquid impregnation method followed by a calcination process in this study. And the as-prepared materials were comprehensively investigated by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectra, UV-vis diffuse reflectance spectroscopy, photoluminescence spectra and N 2 adsorption-desorption. The resultant TiO 2 materials exhibit unique morphology, in which the curly nanofibers with the diameter about 90 nm interweave each other for assembling hierarchical mesh structures and there are abundant grooves on the surface of the nanofibers. During the bio-inspired synthetic process, the PPs play important roles as template and induction for forming the hierarchical mesh structures of TiO 2 nanofibers. Furthermore, some of the as-prepared TiO 2 samples exhibit 99% degradation rate for methyl orange in 30 min under UV light irradiation, which can be ascribed to the larger surface area and the unique hierarchical mesh structures. In addition, the stability tests of 5 cycling runs of the photocatalysts indicate that the as-prepared TiO 2 nanofibers can be applied as a practical photocatalyst for degrading organic dyes under UV light irradiation. Therefore, hopefully, the strategy for preparing the TiO 2 nanofibers can be extended to design many more powerful photocatalysts for the environmental remediation in the near future.

The electrostatic induced self-assembly method is successfully applied to prepare core-shell hierarchical structure of BiOI/OMCMB (Oxidized mesocarbon microbead) composites (MB), in which BiOI nanosheets were uniformly immobilized on the surface of OMCMB. The low-priced graphite carbon OMCMB played a crucial role in inducing and assembling the core-shell structure of the MB composites, which not only effectively improved the conductivity of the catalyst, but also enhanced the stability of BiOI in the catalytic process. The photocatalytic degradation of tetracycline hydrochloride (TH) revealed that the hierarchical structure of OMCMB and BiOI promoted the photogenerated charge separation, and enhanced the photocatalytic performance of BiOI. And sample MB-3 had the highest photocatalytic performance with TH degradation of 96.8 % under the visible-light irradiation for 60 min. MB-3 remains favorable photocatalytic activity after four cycles. Moreover, based on the related optical and electrical characterization analysis, a possible photocatalytic mechanism about MB composites was proposed tentatively.

A novel method for modifying C.I. Pigment Red 21 with sepiolite and lithopone was applied during its preparation process. The morphology and structure of the modified pigment were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) spectroscopy. The results showed that sepiolite was encapsulated by the organic pigment and lithopone was deposited on the surface of the organic pigment. The particle size of the modified pigment was comparable to that of the original pigment, but the modified pigment had a narrower scatter of diameter and a higher homogeneity than the original pigment. The properties of the modified pigment including tinctorial strength and flowability were slightly improved, and its heat resistance and light fastness were enhanced by 20 °C and one grade, respectively. Thermal and UV analyses showed that the thermo- and photostabilities of the modified pigment were significantly improved.

In this paper, TiO2 photocatalyst sensitized with commercial organic pigment, C.I. Pigment Yellow 154 (PY) or C.I. Pigment Red 254 (PR) was prepared by solvothermal method, respectively. Photocatalytic activities of the as- prepared pigment/TiO2 composites was evaluated by the degradation of the methyl orange (MO) under visible light irradiation. Microstructural, morphological, and optical properties of the as-prepared pigment/TiO2 composites were characterized by X-ray diffraction technique (XRD), BET surface area analysis, UV–vis diffuse reflectance spectrum (UV–vis DRS). Results displayed that the as-prepared pigment/TiO2 composites have high visible light photocatalytic activity and stability. The TOF of pigment/TiO2 based on the content of pigment had nearly loss when the photocatalyst was used four times. The remarkable enhancement in the visible light photocatalytic activities of the pigment/TiO2 heterostructures could be attributed to the effective electron–hole separations at the interfaces of the two semiconductors.

Nano-scale TiO(2) photocatalysts co-doped by rare earth ions (La(3+), Ce(3+)) and heteropolyacids were designed and prepared by sol-gel method to probe synergistic effect on photocatalytic elimination of organic compounds, and their physicochemical properties were characterized by X-ray diffraction (XRD), specific surface area and porosity (BET and BJH), high resolution transmission electron microscopy (HRTEM), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), and X-ray photoelectron spectroscopy (XPS) as well as Raman spectroscopy. The photocatalytic activity of prepared catalysts was evaluated by the degradation of methylene blue (MB) in water under UV-light irradiation. The results showed that the co-doping of the rare earth ions and heteropolyacids can significantly improve the photocatalytic activity of prepared composite photocatalysts due to the efficient inhibition of the recombination of photogenerated electron-hole pairs. The enhancement mechanism of co-doping of the rare earth ions and heteropolyacids on TiO(2) is also discussed.

Rare earth ions La3+ and Eu3+ co-doped TiO2 photocatalyst (La-Eu/TiO2) was prepared by sol-gel method, and characterized by various techniques such as X-ray diffraction (XRD), specific surface area and porosity (BET and BJH), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), UV-vis diffuse reflectance spectroscopy (DRS) and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of the La-Eu/TiO2 was evaluated by the degradation of methylene blue (MB) under UV light irradiation. The catalyst had a relatively uniform particle diameter distribution in the range of 40–60 nm. When calcining at 600°C, the XRD patterns of La-Eu/TiO2 indicated the anatase phase, while the XPS patterns showed the Ti4+, La3+ and Eu3+ ions existence. The DRS spectra showed red shift in the band-gap transition. The experimental results of MB degradation demonstrated that the photocatalytic activity of La-Eu/TiO2 was significantly enhanced due to better separation of photogenerated electron-hole pairs.

Er3+, montmorillonite (MMT) and H3PWl2O40 co-doped TiO2 photocatalyst (Er-H3PWl2O40-MMT/TiO2) was prepared by sol-gel method, and characterized by X-ray diffraction (XRD), specific surface area and porosity (BET and BJH), high resolution transmission electron microscopy (HRTEM) and Raman spectrum. The photocatalytic activity of the Er-H3PWl2O40-MMT/TiO2 was evaluated by the degradation of methylene blue (MB) under UV light irradiation. The experimental results of MB degradation demonstrated that the photocatalytic activity of Er-H3PWl2O40-MMT/TiO2 was significantly enhanced due to better separation of photogenerated electron-hole pairs, and its activity was absolutely higher than P-25 TiO2.

Sodium benzene sulfonate (BS) was decomposed in aqueous TiO 2 dispersions under highly concentrated solar light illumination to examine the photocatalytic characteristics of a parabolic round concentrator (PRC) reactor to degrade the pollutant without visible light absorption. The effects of such operational parameters as initial concentration, volume of the aqueous BS solution, oxygen purging, and TiO 2 loading on the kinetics of decomposition of BS were investigated. An effective photodegradation necessitates a suitable combination of initial volume and concentration of BS solution. Relative to atmospheric air, oxygen purging significantly accelerates the degradation process at high initial concentrations of BS (0.40 mM or 1.0 mM). Optimal TiO 2 loading was 9 g l −1 , greater than previously reported. Elimination of TOC (total organic carbon) followed pseudo first-order kinetics in the initial stages of the photodegradation process. The relative photonic efficiency for the photodegradation of BS is ζ rel =1.0.

La and Y co-doped TiO2 nano photocatalyst (La-Y/TiO2) was prepared by sol-gel method, and characterized by X-ray diffraction (XRD), specific surface area (BET), scanning electron microscope (SEM) and high resolution transmission electron microscopy (HRTEM). The photocatalytic activity of the La-Y/TiO2 was evaluated by the degradation of methylene blue (MB) under UV light. Parameters effecting photocatalytic process such as La and Y doping concentration, calcination temperature, the dosage of catalyst and the pH of MB solution were investigated. The co-doped TiO2 catalyst showed obviously higher photocatalytic activity for the degradation of methylene blue (MB). The presence of La and Y ions in the TiO2 particles would prevent the recombination of the electron-hole on the surface of TiO2 effectively.