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Exploring efficient adsorbents still remains an important challenge due to the poor efficiency of the reported adsorbents for the adsorption of antibiotics. Herein, we design and prepare a novel nanosheets-like hollow TiO 2 (NHT) adsorbent by using hollow TiO 2 as a precursor through alkaline hydrothermal treatment. Adsorption results show that NHT exhibits a high adsorption percentage (98.05%) within 20 min and a maximum adsorption uptake of 24.51 mg/g for Levofloxacin (LVOF) pollutant (10 mg/L, 50 mL), which is 17 times higher than that (1.4 mg/g) of pristine hollow TiO 2 (HT). Notably, NHT realizes >91% of the adsorption percentage for LVOF pollutant after the tenth run only through photo-regeneration without extra post-treatments, effectively overcoming the disadvantages of harsh regeneration procedures for most of the existed adsorbents. Adsorption data and the performance characterizations present deep insights into adsorption mechanism, which reveals that pore filling effect, hydrogen-bond interactions, and electrostatic attraction are the key parameters for the excellent adsorption of LVOF by NHT. Therefore, the present study can provide a promising direction for the fabrication of efficient adsorptive photocatalyst by using low-cost TiO 2 as a precursor. [Display omitted] • Novel nanosheets-like hollow TiO 2 (NHT) adsorbent was prepared via a facile alkaline hydrothermal treatment. • NHT adsorbent exhibited higher adsorption capacity of LVOF and faster adsorption kinetics than the present materials. • NHT manifested efficient adsorption of LVOF in ambient factors and real water matrices. • Exceptional levofloxacin adsorption/photo-regeneration cycles were realized by NHT adsorptive photocatalyst. • The efficient adsorption mechanism was ascribed to pore-filling effect, hydrogen bonding, and electrostatic interactions. [ABSTRACT FROM AUTHOR]

Exploring inorganic flower-like nanosheets is of increasing interest not only for fundamental research, but also for development of devices due to their good chemical stability, versatility, and high surface-to-volume ratio. In this work, flower-like TiO2 nanosheets (FTN) are successfully synthesized by a facile hydrothermal method. Notably, a series of single-factor experiments are carried out to drive multiple functional components in order to integrate into a single flower-like nanostructure perfectly. In addition, these experimental results further reveal that alcohol/glycerol molar ratio acts in a vital role for preparing optimal flower-like morphology and structure of TiO2. Furthermore, the photodegradation pathways and mechanism of Levofloxacin (LVOF) by FTN are shown according to photodegradation intermediates of LVOF, trapping experiments, and ligand-to-metal charge transfer (LMCT) sensitizing effect. Therefore, the present work not only demonstrates the controlled synthesis of flower-like TiO2 nanosheets, but also provides a guide for constructing other inorganic flower-like nanosheets or TiO2-based photocatalysts with optimal morphology, structure and photocatalytic performance. [ABSTRACT FROM AUTHOR]

Constructing phase junction is an effective strategy to increase photocatalytic performance of titanium dioxide (TiO 2) because it can promote charge separation. However, both low surface area and unstable phase interface limit its further application. In this investigation, we introduce a structural regulation strategy to prepare anatase/rutile TiO 2 (A/R–TiO 2) hollow photocatalyst through in-situ growth of rutile TiO 2 on anatase TiO 2 hollow microspheres byheat treatment. The as-synthesized A/R–TiO 2 photocatalyst was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and ultraviolet–visible (UV–vis) spectroscopy. The results reveal that the A/R–TiO 2 hollow photocatalyst significantly promotes efficient charge separation due to the intimate contact of two phases within a single hollow sphere. Notably, A/R–TiO 2 exhibits more efficient than commercial TiO 2 (P25) towards the photodegradation of various pesticide pollutants, which suggests that such a structural design can be an effective method for rationally constructing TiO 2 -based photocatalyst with advanced performance. [Display omitted] • A/R–TiO 2 hollow photocatalyst was prepared through in-situ growth of rutile TiO 2 on anatase TiO 2. • A/R–TiO 2 exhibited more efficient than commercial TiO 2 (P25) in pesticides degradation. • The combination of heterophase homojunction and hollow structure was the key parameter in photocatalysis. • The A/R–TiO 2 heterophase homojunction suppresses the bulk recombination of photoinduced carriers. • The degradation pathways and charge transfer mechanism were detailed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Activated carbon modified TiO 2 /Bi 2 O 3 adsorbent was prepared by a one-pot hydrothermal method. • Low temperature calcination (280 °C) led to high surface area (188.49 m2/g) of TiO 2 /Bi 2 O 3 /AC. • The integrated adsorbent/photocatalyst system promoted high removal efficiency of organic pollutants. • The efficient adsorption and photo-regeneration mechanism of tetracyclines were detailed. Considerable endeavors have focused on tightly combining adsorption with photocatalysis in designing composite materials for environmental pollution treatment. Recent advances in coupling titanium dioxide/bismuth trioxide (TiO 2 /Bi 2 O 3) with activated carbon (AC) show significantly enhanced photocatalytic performance but face critical limitations including low adsorption capacity and multi-step synthesis. In this work, we introduce a one-pot synthesis of activated carbon modified TiO 2 /Bi 2 O 3 composite materials (TiO 2 /Bi 2 O 3 /AC). Thanks to the integrated adsorbent/photocatalyst system, TiO 2 /Bi 2 O 3 /AC shows a drastically enhanced removal efficiency for sulfamethazine (>81%), far beyond the corresponding value of the reported AC/TiO 2 /Bi 2 O 3 adsorbent (<40%). Notably, the removal rates of other typical pollutants including tetracyclines, methyl orange, and rhodamine B are as high as >98%. Furthermore, TiO 2 /Bi 2 O 3 /AC obtains >80% of its adsorption rate for the fifth cycle after simple photo-regeneration without any other post-treatments. Kinetic analysis and photoelectric characterization are carried out to provide insight into adsorption mechanism. Therefore, this work demonstrates a considerable potential to design and construct other multifunctional adsorbents with advanced performance. [ABSTRACT FROM AUTHOR]

Considerable efforts have focused on pursuing the efficient removal of antibiotic contaminants by combining adsorbents with photocatalysts. However, the reported adsorbents/photocatalysts still suffer from critical drawbacks including low adsorption rate, low mineralization rate, and complicated preparation procedures, greatly restricting their practical application. In this work, we report a facile method to develop porous TiO 2 /BiOI adsorbent through a one-pot hydrothermal process and subsequently low-temperature calcination (280 °C). Adsorption experiment shows that porous TiO 2 /BiOI realizes almost complete removal (99.4%) of tetracyclines, far beyond the values of BiOI (20.2%) and TiO 2 (71.1%). Notably, one-pot synthesis promotes the mass production of TiO 2 /BiOI without obvious loss in adsorption capacity. More importantly, TiO 2 /BiOI adsorbent can be simply regenerated by complete photodegradation of the adsorbed tetracyclines on TiO 2 /BiOI, and regains above 98% of its adsorption capacity for 10 cycles, successfully overcoming the limitations of environment-unfriendly regeneration conditions, low adsorption capacity, and poor recyclability for most of the reported adsorbents/photocatalysts. Additionally, adsorption mechanism is deduced to be mainly electrostatic attraction, hydrogen bonding, and pore filling according to adsorption performance. Therefore, the design concept we present here provides a new perspective for the development of reactive adsorbents with excellent removal efficiency and recyclability through a facile one-pot synthesis. [Display omitted] • TiO 2 /BiOI reactive adsorbent was prepared by a facile one-pot hydrothermal method. • TiO 2 /BiOI showed excellent removal (>99%) of tetracycline from aqueous solution. • One-pot strategy realized the mass production of TiO 2 /BiOI without obvious loss in adsorption capacity. • TiO 2 /BiOI exhibited superior recyclability (>98%) up to 10 cycles of photo-regeneration and re-adsorption. • Key removal mechanism of tetracyclines was detailed. [ABSTRACT FROM AUTHOR]

How to promote the solar conversion efficiency of photoelectrochemical water splitting still remains a big challenge. In this work, we design a new 3D inverse opal ZnO/ZnS (IO–ZnO/ZnS) heterojunction by coupling polystyrene-templating with in-situ sulfidation. Thanks to 3D inverse opal structure and Z-scheme mechanism, the IO-ZnO/ZnS photocatalyst shows excellent photocurrent density (0.12 mA cm−2) and H 2 evolution rate (101.40 μmol/g/h) without any sacrificial agent, which is among the comparable values with the reported ZnO–ZnS based photocatalysts. Clearly, its unique interconnected pore structures offer abundant photocatalytic active sites and improved light utilization due to multiple light reflections. And, Z-scheme heterojunction facilitates the effective electron-hole separation, greatly driving hydrogen evolution. Notably, the thickness (1–7.5 μm) of IO-ZnO/ZnS is easy to be controlled by simply tailoring the initial concentration of polystyrene template, obtaining the optimally photocatalytic performance of IO-ZnO/ZnS. Therefore, this design concept can be expanded to construct other composite photoanode materials for energy storage and conversion application. [Display omitted] • 3D Inverse Opal ZnO/ZnS heterojunction was prepared by combining polystyrene-templating with in-situ sulfidation process. • The thickness of IO-ZnO/ZnS was easy to be controlled by tailoring the initial concentration of polystyrene template. • IO-ZnO/ZnS showed excellent photocurrent density and H 2 evolution rate without sacrificial agent. • The photocatalytic mechanism of efficient hydrogen evolution was proposed. [ABSTRACT FROM AUTHOR]

Coupling morphology modification with heterojunction is an effective strategy to promote the photocatalytic activity of TiO 2 -based photocatalysts for wastewater treatment. In this work, we devise a novel flower-like TiO 2 /Bi 2 O 3 (FTB) photocatalyst through the deposition of Bi 2 O 3 nanoparticles on the surface of flower-like TiO 2 (FT). Various characterization techniques reveal the successful construction of p-n heterojunction at the interfaces of flower-like TiO 2 and Bi 2 O 3 , which promotes efficient charge separation. Benefiting from the narrow bandgap of Bi 2 O 3 and flower-like microstructure, the photocurrent of FTB is about 1.67 times higher than that of FT, leading to higher photo-degradation rate (92.7%) of levofloxacin than that (∼80%) of FT photocatalyst. More important, FTB presents a good anti-interference capability for environmental factors including solution pH, ionic strength, and water matrix. Additionally, the photocatalytic performance and microstructure of FTB photocatalyst remain unchanged before and after five cycles, suggesting a good cyclability. Therefore, this work offers a new insight in constructing TiO 2 -based photocatalysts with advanced performance for efficient removal of antibiotics. [Display omitted] • Flower-like TiO 2 /Bi 2 O 3 was prepared via hydrothermal synthesis and photo-deposition. • Flower-like structure and p-n heterojunction promoted fast charge separation and transfer. • The introduction of flower-like structure strengthened the levofloxacin degradation. • The efficient degradation pathway and mechanism of LVOF were detailed. [ABSTRACT FROM AUTHOR]

Combining heterojunction with advanced structures is a promising tool to enhance the photoelectrochemical performance of semiconductor photocatalysts for environmental remediation. Herein, a novel multi-heterojunction TiO 2 @Bi 2 O 3 (MHTB) hollow photocatalyst is successfully constructed by loading Bi 2 O 3 nanoparticles on the surface of inner TiO 2 and outside of TiO 2 shell. Photoelectrochemical characterizations show that the formation of multiple heterojunctions at the TiO 2 @Bi 2 O 3 interfaces facilitates faster separation and transfer of photoinduced charge carriers than that of conventionally reported p-n heterojunction photocatalysts. Because of the separated two layers of Bi 2 O 3 and unique hollow structure, the photocatalytic performance of MHTB is significantly improved, leading to excellent photo-degradation rate constant (k = 0.0165 min−1) for the degradation of levofloxacin, which approaches 1.5-fold and 2.6-fold increase than that of TiO 2 @Bi 2 O 3 @TiO 2 (n-p-n heterojunction) and TiO 2 @Bi 2 O 3 (n-p heterojunction), respectively. Notably, the MHTB photocatalyst exhibits an excellent anti-interference capability for the interference of environmental factors. Moreover, the photocatalytic activity, crystal structure, and bonding energy of MHTB photocatalyst remain unchanged after being used several times, indicating an excellent stability. Therefore, this finding opens a new door to develop highly active photocatalysts with multiple heterojunctions for efficient pollutant removal and environmental remediation. [Display omitted] • Multi-heterojunction TiO 2 @Bi 2 O 3 photocatalyst (MHTB) was prepared for the first time. • MHTB drove the efficient degradation (>98%) and mineralization (92.6%) of levofloxacin under visible light. • Multi-heterojunction and hollow structure contributed to the degradation of levofloxacin. • The degradation pathway and mechanism of levofloxacin was proposed. [ABSTRACT FROM AUTHOR]

Catalytic reduction of nitroarenes and unsaturated aldehydes to corresponding hydrogenated products is an environment-friendly technology to prepare industrially important intermediates. however, high chemoselectivity still remains a big challenge when a nitroarene or unsaturated aldehyde molecule with two or more reducible groups. Herein, we construct a novel confined catalyst by encapsulating Ag NPs into the nanospace of hierarchical hollow silica (SiO 2 -Ag@void@SiO 2), enabling the excellent chemoselective hydrogenation (>99%) of 2-nitrochlorobenzene and cinnamyl aldehyde into corresponding amino groups (-NH 2) and hydroxyl groups (-OH) without hydrogenating other functional groups (-Cl and C C). The unique hydrogenation performance is identified to be associated with the confinement effect and highly dispersed Ag NPs because hydrogenation reaction takes place within the confined silver nanospace. Therefore, our study provides a guide to construct highly active catalysts for chemoselective catalysis. [Display omitted] • A novel confined catalysts by embedding silver into the nanospace of hierarchical hollow silica was prepared. • The confined catalyst exhibited excellent chemo-selectivity (>99%) of 2-NCB and CA at room temperature. • the confined nanospace promoted the excellent hydrogenation performance than the reported metal-supported catalysts. • This work provides a guide to construct highly active catalysts for chemo-selective catalysis of organic conversions. [ABSTRACT FROM AUTHOR]

[Display omitted] • The p-n heterojunction Bi 2 O 3 /Ti3+-TiO 2 photocatalyst was reported by a facile method. • The Bi 2 O 3 /Ti3+-TiO 2 enabled the complete removal (100%) of tetracyclines under visible light. • The effect of environmental factors on the photodegradation of tetracyclines was detailed. • The mechanism on photodegradation was analyzed through LC–MS spectrum. The search for a highly active visible-light photocatalyst toward the complete degradation of antibiotic residuals remains a challenging task due to the fast emergence of antibiotic resistance. To address the problem, we explore a novel p-n heterojunction visible-light photocatalyst by coupling a p-type Bi 2 O 3 with an n-type Ti3+ self-doped TiO 2 porous material. The as-synthesized photocatalyst exhibits a narrowed bandgap (~2.89 eV) and enhanced visible-light absorption, leading to the complete degradation (100%) of antibiotics under visible light irradiation (λ > 420 nm) and excellent recyclability (98%) because of the synergistic effect of Ti3+ self-doping and p-n heterojunction. The results effectively work out the challenging task of the incomplete removal of tetracyclines over almost all of the reported visible-light photocatalysts. Additionally, the effects of antibiotics mixture, pH value, inorganic ions, water matrix, and outdoor light on the degradation of tetracyclines were also detailed. Especially, the transformation pathways and degradation mechanism of tetracycline were revealed in depth via trapping experiments and photoelectrochemical characterizations. Therefore, this work provides a new insight in exploring excellent photocatalysts to realize the complete removal of other refractory organic pollutants under visible light. [ABSTRACT FROM AUTHOR]