Photocatalytic Capability Research Articles

Sol-Gel Multilayered Niobium (Vanadium)-Doped TiO2 for CO Sensing and Photocatalytic Degradation of Methylene Blue.

Multilayered TiO2 films doped either with Niobium or Vanadium (1.2 at. %) were deposited by the sol-gel dip coating method on c-Si and glass substrates. The films on glass substrates were tested for CO sensing and photocatalytic degradation of methylene blue. X-ray diffraction data analysis showed that all the TiO2:Nb(V) films were nanocrystalline in the anatase phase, with a uniform and compact microstructure and a homogeneous superficial structure of small grains with diameters in the range of 13-19 nm. For the electrical characterization, the TiO2:Nb(V) films were incorporated in Metal-Insulator-Semiconductor (MIS) structures. The specific resistivity is of the order of 104 Ωcm and its value decreases with increasing the electrical field, which testifies to the injection of electrons into these layers. From the analysis of the current-voltage curves taken at different temperature- and frequency-dependent capacitance-voltage and conductance-voltage characteristics, the density and parameters of deep levels in these TiO2 films are evaluated and the electron charge transport mechanism is established. It was shown that the current in these TiO2:Nb(V)-Si MIS structures is mainly carried out by inter-trap tunneling via deep levels energetically distributed in the TiO2 bandgap. Testing these sol-gel TiO2:Nb(V) layers for gas sensing and photocatalytic capabilities proved that they could serve such purposes. In particular, the results of the V-doped sol-gel TiO2 film confirm its CO detection capability, which is rarely reported in the literature. For the photodegradation of methylene blue, the Nb-doped TiO2 samples were superior, with nearly double the photocatalytic efficiency of undoped TiO2.

Noble-Metal-Free High-Entropy Alloy Nanoparticles for Efficient Solar-Driven Photocatalytic CO2 Reduction.

Metal nanoparticle (NP) cocatalysts are widely investigated for their ability to enhance the performance of photocatalytic materials; however, their practical application is often limited by the inherent instability under light irradiation. This challenge has catalyzed interest in exploring high-entropy alloys (HEAs), which, with their increased entropy and lower Gibbs free energy, provide superior stability. In this study, 3.5nm-sized noble-metal-free NPs composed of a FeCoNiCuMn HEA are successfully synthesized. With theoretic calculation and experiments, the electronic structure of HEA in augmenting the catalytic CO2 reduction has been uncovered, including the individual roles of each element and the collective synergistic effects. Then, their photocatalytic CO2 reduction capabilities are investigated when immobilized on TiO2. HEA NPs significantly enhance the CO2 photoreduction, achieving a 23-fold increase over pristine TiO2, with CO and CH4 production rates of 235.2 and 19.9µmol g-1 h-1, respectively. Meanwhile, HEA NPs show excellent stability under simulated solar irradiation, as well high-energy X-ray irradiation. This research emphasizes the promising role of HEA NPs, composed of earth-abundant elements, in revolutionizing the field of photocatalysis.

Synthesis and Characterization of Superhydrophobic Epoxy Resin Coating with SiO2@CuO/HDTMS for Enhanced Self-Cleaning, Photocatalytic, and Corrosion-Resistant Properties.

The exceptional corrosion resistance and combined physical and chemical self-cleaning capabilities of superhydrophobic photocatalytic coatings have sparked significant interest among researchers. In this paper, we propose an economical and eco-friendly superhydrophobic epoxy resin coating that incorporates SiO2@CuO/HDTMS nanoparticles modified with Hexadecyltrimethoxysilane (HDTMS). The application of superhydrophobic coatings effectively reduces the contact area between the metal surface and corrosive media, leading to a decreased corrosion rate. Additionally, the incorporation of nanomaterials, exemplified by SiO2@CuO core-shell nanoparticles, improves the adhesion and durability of the coatings on aluminum alloy substrates. Experimental data from Tafel curve analysis and electrochemical impedance spectroscopy (EIS) confirm the superior corrosion resistance of the superhydrophobic modified aluminum alloy surface compared to untreated surfaces. Estimations indicate a significant reduction in corrosion rate after superhydrophobic treatment. Furthermore, an optical absorption spectra analysis of the core-shell nanoparticles demonstrates their suitability for photocatalytic applications, showcasing their potential contribution to enhancing the overall performance of the coated surfaces. This research underscores the promising approach of combining superhydrophobic properties with photocatalytic capabilities to develop advanced surface modification techniques for enhanced corrosion resistance and functional properties in diverse industrial settings.

A nanocomposite containing orange emissive quantum dots for degradation of fluorescein sodium

Obtaining high-efficiency photocatalytic materials responsive to visible light is crucial to eliminating organic dye pollution in industrial wastewater. The paper describes the optical characteristics of ZnO-decorated visible-light-responsive orange-emitting carbon quantum dots ZnO (ZnO/O-CQDs composites). The composite was tested for its photocatalytic capabilities through the photodegradation of fluorescein sodium, a dye. Despite its vast usage and irritant properties, this is the first report on the photodegradation of fluorescein sodium using a customized ZnO/CQDs photocatalyst. Under visible light, the photocatalytic degradation efficiency reached 96.3 % over just 40 min. We also investigated the structural and elemental composition of the ZnO/O-CQDs using TEM, FESEM, EDS, and XPS. The results confirm that O-CQDs with varying properties promote ZnO's photocatalytic activity. The degradation obeyed the pseudo-first-order kinetics model with a photocatalytic rate constant (k) of 0.082 min−1, significantly higher than that of pure ZnO (0.048 min−1).

BiOCl modified TiO2 based catalyst with enhanced hydrogen generation properties under visible light via promote photogenerated electron-hole separation

Due to its wide band gap and low photogenerated carrier separation efficiency, TiO2 has an undesirable photocatalytic activity. In the present work, BiOCl was hydrothermally deposited on TiO2 and BiOCl/TiO2 composites with different ratios were obtained. The results show that 30 % BiOCl/TiO2 has the best performance of 1354.94 μmolg−1h−1, which is 18.4 times than pure TiO2 and 73.1 times than pure BiOCl. The significant increase in the photocatalytic efficiency of BiOCl/TiO2 composites is attributed to the reduction of their bandgap width and the fast separation of photogenerated electron-hole pairs. This work brings a new idea to increase the photocatalytic hydrogen production capability of TiO2.

Harnessing In2O3 as an electron aggregator to assist BiOBr nanosheets for enhanced photocatalytic CO2 reduction activity

The advancement of catalysts featuring high carrier separation efficiency enhances photocatalytic reduction performance. This study employed a simple hydrothermal method to anchor In2O3 nanoparticles onto the surface of two-dimensional BiOBr nanosheets, constructing a type-II heterostructure that improves the photocatalytic reduction capability. The composites of 0D/2D In2O3/BiOBr underwent XPS, TPR, and MS characterization, validating the formation of a type-II heterostructure. In2O3 functioned as an electron-aggregating active site that extracted photogenerated electrons from the surface of BiOBr. As a result, the efficiency of charge separation is markedly increased. The results of the CO2 reduction test indicate that In2O3-modified BiOBr exhibits superior photocatalytic activity compared to pure BiOBr, with 2 % In2O3/BiOBr exhibiting the highest reduction performance. The CO yield achieved was 9.81 µmol·g−1·h−1, which is 5.33 times higher than that of pure BiOBr and 42.65 times higher than that of pure In2O3. These findings offer future potential for the application of In2O3 as an electron-accumulating material to enable the photocatalytic reduction of CO2.

Mechanistic exploration in controlling the product selectivity via metals in TiO2 for photocatalytic carbon dioxide reduction

Harnessing the power of the sun, the photocatalytic CO2 reduction process emerges as a pivotal sustainable solution, utilizing solar energy a premier, clean energy source known for its efficiency and economic viability in the current energy paradigm. This study investigates the impact of metals (Cu, Ag, Au) on enhancing the photocatalytic CO2 reduction capabilities of TiO2. In-depth mechanistic analysis conducted using in-situ DRIFTS for identifying the key reaction intermediates, highlights that the catalytic performance, both in terms of activity and product selectivity, is tightly linked to the underlying reaction mechanisms route, optoelectronic properties, and substrate’s (CO2 and H2O) affinities to the catalyst surface. Enhanced light absorption and reduced charge recombination (lifetime enhancement from 0.21 ns to ∼1.2 ns) in case of metal incorporated resulted in enhanced overall photocatalytic performance. With Au as dopant, demonstrated highest electron selectivity for H2 (>97%) compared to Ag and Cu, which showed relatively higher CO2 reduction electron selectivity (∼20% for Cu). The study reveals the crucial interplay of intermediate stabilization, demonstrating its critical role in governing the reaction pathways i.e., carbene or formaldehyde routes as observed in case of Ag and Cu respectively and thus the specific final products. For enhancing the selectivity of CO, engineering the catalyst surface to favour weak CO adsorption is vital. Observations in the CO-TPD measurements demonstrated that Ag sites were effective in promoting the weaker CO* stabilization thus displayed more selectivity towards CO as compared to Cu. While higher CH3OH formation rates in case of Cu, were found to be related to the augmented reactive M=O species stabilization which promotes the oxidation of CH4 to CH3OH. Additionally, in case of Cu, the CH3O* intermediates stabilized effectively, which contributed to more Methanol selectivity through favoured formaldehyde route. While in case of Ag, the CH2* stabilization suggests more probability of the carbene pathway in comparison to the formaldehyde route (as in case of Cu) for producing the CH4 as the final hydrogenated C1 product. These insights guide the strategic design of catalysts for controlling the reaction pathways and thus selective C1 product production in photocatalytic CO2 reduction, offering insights for advanced catalyst design.

Au/Ag2MoO4 nanocomposite: A dual-function catalyst for dye degradation and colorimetric detection

The authors have successfully synthesized a distinctive potato-shaped Au/Ag2MoO4 nanocomposite with exceptional photocatalytic capabilities in the degradation of methylene blue (MB) under UV irradiation even in neutral conditions. Furthermore, this material displays noteworthy peroxidase-like oxidation activity, facilitating the detection of hydrogen peroxide (H2O2) and ascorbic acid (AA) in aqueous environments. This detection method relies on the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB). The signal generated by TMB adsorption on the catalyst's surface plays a pivotal role in the oxidation of TMB in the presence of H2O2, resulting in the formation of a distinct blue-colored product. This reaction is equally influenced by the presence of AA, which, owing to its antioxidant properties, impedes the development of the color signal. This colorimetric approach exhibits high sensitivity, boasting low limits of detection (LOD) and quantification (LOQ) of 0.0252 and 0.0839 mM for H2O2, and 1.7724 and 5.7109 mg/L for AA, respectively. The method offers a broad linear range spanning from 0.029 to 26.47 mM for H2O2 and 0–40 mg/L for AA with a straightforward, cost-effective analytical procedure, and yields highly reliable results. The proposed method displays superior selectivity in detecting AA and high anti-interference capabilities. These findings underscore the photocatalytic and peroxidation-like activities of Au/Ag2MoO4 nanocomposite, positioning it as a promising candidate for various biomedical applications.

Sol-Gel technique, characterization and photocatalytic degradation activity of Manganese doped ZnO nanoparticles

Photocatalysis using semiconductor metal oxide stands out as a highly effective and efficient method for eliminating organic pollutants from wastewater. This study aims to assess the photocatalytic capabilities of Mn doped ZnO nanocomposites in degrading methylene blue (MB) dye under ultra-violet light exposure. This study details the synthesis of ZnO photocatalysts through a straightforward one-step sol-gel method, incorporating varying levels of Mn-doping (0%, 2% & 4%). The structural and optical attributes were examined using techniques such as powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and UV-Vis diffuse reflectance spectra. X-ray diffraction analyses verified the presence of a hexagonal wurtzite crystal structure in all synthesized samples, exhibiting a high degree of crystallinity. In addition, an investigation into the impact of Mn impurities on the photocatalytic performance of ZnO catalysts was conducted in the context of methylene blue (MB) degradation. The experimental findings revealed that the Mn doped ZnO nanoparticles produced exhibited significantly superior photocatalytic performance compared to pure ZnO when used in breaking down methylene blue under UV-light exposure. This study proposes that these Mn doped ZnO could serve as a highly effective photocatalyst for treating water contaminated with certain chemically persistent synthetic organic dyes. The improved photocatalytic capabilities of ZnO nanostructures doped with Mn were ascribed to the synergistic impact of increased surface area in ZnO nanosphere and enhanced efficiency in charge separation resulting from optimized Mn doping. A potential explanation for the heightened photocatalytic performance of Mn-doped ZnO nanostructures is proposed tentatively.

Enhanced inactivation of Staphylococcus aureus and Escherichia coli using conjugated polyindole polymer nanoparticles under visible light irradiation

AbstractThe areas of environmental cleanup and bacteria inactivation are particularly interesting in polymer‐based nanomaterials because of their unique physicochemical properties. Conjugated polymer nanoparticles (CP NPs) have potential uses in the biological and environmental, but little is known about them. This study aimed to examine the efficacy of CP nanoparticles in the photocatalytic inactivation of S. aureus and E. coli under visible irradiation (λ ≤ 420 nm), with minor enhancements observed. The simple and one‐step chemical oxidation technique was used to prepare CP nanoparticles. X‐ray powder diffraction (XRD), Fourier‐transform infrared spectroscopy (FT‐IR), Scanning electron microscope (SEM), Energy‐dispersive X‐ray (EDS), and Transmission electron microscopy (TEM) analyses were utilized to characterize the physicochemical properties of CP nanoparticles for comprehensive structural analysis. The synthesized CP nanoparticles exhibited outstanding photocatalytic disinfection capabilities, achieving a degradation of 98.6%. This research not only provides insights into the physical characteristics of CP nanoparticles but also illustrates their antibacterial efficacy against two different bacterial pathogens, namely S. aureus and E. coli. Therefore, this research highlights an eco‐friendly and inexpensive preparation of conjugated polymer nanoparticles for a wide range of applications.

Improved photocatalytic performance via air‐plasma modification of titanium dioxide: Insights from experiments and simulations

AbstractCommercial titanium dioxide is successfully plasma‐treated under ambient conditions for different periods, leading to reduced crystallite size and the creation of oxygen vacancies. Density functional theory‐based calculations reveal the emergence of additional localized states close to the conduction band, primarily associated with under‐coordinated titanium atoms in non‐stoichiometric titanium‐oxide systems. The plasma‐treated samples exhibit improved photocatalytic performance in the degradation of methylene blue compared to untreated samples. Moreover, the 4‐hour plasma‐treated photocatalyst demonstrates commendable stability and reusability. This work highlights the potential of cost‐effective plasma treatment as a simple modification technique to significantly enhance the photocatalytic capabilities of titanium‐oxide materials.

“Light battery” role of long afterglow phosphor for round-the-clock environmental photocatalysis

Owing to its convenient, sustainable and green process, photocatalysis has become a feasible technique for solving environmental pollution issues. So far, significant achievements have been realized in photocatalytic pollutant elimination. Nevertheless, photocatalytic processes require a continuous external light illumination to drive photoredox reactions, seriously prohibiting their applications in darkness. In this context, exploring a photocatalyst with reliable photocatalytic activity in dark condition is therefore highly meaningful and an ultimate target of photocatalysis technique. Recently, long afterglow phosphor has aroused great attention due to its “light battery” role for driving catalytic reactions in dark conditions. To be specific, long-afterglow phosphor or long-afterglow phosphor/semiconductor composite can be used as a photocatalyst to simultaneously promote the photoredox processes and store extra photoexcited charges in the trapping states upon light irradiation. When the light illumination terminates, a gradual release of the charges from trapping states occurs in long-afterglow phosphor, which can continuously spur photoredox reactions under the dark environment and even maintains the photocatalysis around the clock. In this work, we comprehensively reviewed the recent advances of long afterglow phosphor based round-the-clock photocatalysts in environmental pollutant elimination. Meanwhile, the inherent mechanism of long afterglow photocatalysis was discussed in depth. More importantly, the relationship between the improved long afterglow photocatalytic capability and the engineering of long afterglow system is correlated systematically. Finally, the ongoing challenges and future prospects for the mass production and commercial utilization of round-the-clock photocatalysts are analyzed and outlooked.

Syntheses and photochemically antibiotic degradation of two Co(II)-based coordination polymers

Two new Co(II)-based coordination polymers (CPs), designated as [Co2(bbp)4(1,3-bdc)4]n(1) and [Co(bbp)3(NO3)2(H2O)]n(2) (bbp = 3,5-bis(benzoimidazo-1-ly) pyridine; 1,3-H2bdc = 1,3-benzenedicarboxy acid), were synthesized using a dual ligand approach. The characterization of these CPs involved single- crystal -XRD, UV–visible, FT-IR, and TGA analysis. Both CPs 1 and 2 exhibit a distorted octahedral geometry. Both 1 and 2 show a 1D ladder chain, and this chain-like structure undergoes further development into a more intricate two-dimensional (2D) supramolecular network. The thermal stability analysis revealed that 1 and 2 are stable at temperatures of 119 °C and 286 °C, respectively, with no significant mass loss. Notably, both CPs displayed semiconducting properties. The photocatalytic degradation capabilities of CPs 1 and 2 were investigated against antibiotics such as metronidazole (MDZ), Tinidazole (TDZ), ornidazole (ODZ), and furazolidone (FZD). CP 1 exhibits exceptional photocatalytic activity against FZD. A dosage of 5 mg/L of CP 1 resulted in a remarkable degradation efficiency of 92.2 % for 40 ppm FZD. Additionally, a proposed photodegradation mechanism was investigated through radical trapping experiments.

Chinese yam-derived aerogel as a versatile platform for efficient freshwater production and pollution remediation

Water scarcity and pollution have become major obstacles to sustainable global development. The development of a versatile platform that can simultaneously produce clean water and remediate pollutants from water is highly desirable but still difficult to realize. Herein, to address this challenge, we have developed a CY@PPy@Ag aerogel with excellent photothermal and photocatalytic capabilities through a freeze-drying process, followed by polypyrrole coating and Ag deposition. The excellent characteristics, including broad-spectrum light absorption (97.2%), localization of converted heat, rapid water transport, and porous open microchannels, enabled it to act as an advanced solar evaporator for efficient and continuous steam generation without salt crystallization. Moreover, the high evaporation rate (1.51 kg m−2 h−1) was maintained even in high concentrations of brine and real seawater. Taking advantage of its enhanced photocatalytic performance, organic dyes in water could be rapidly and completely decomposed by the CY@PPy@Ag aerogel under solar irradiation, and this photodegradation process was significantly accelerated with the help of NaBH4. This work is expected to provide a one-stone-two-birds strategy to simultaneously achieve clean water harvesting and pollution remediation, which holds great promise in the fields of solar energy harvesting, wastewater treatment, and seawater desalination.

Integrated 2D Bi2O3/boron carbon nitride for improved photocatalytic water depollution

This study delves into the untapped potential of BCN (boron carbon nitride) as a photocatalyst, highlighting its remarkable porosity and bandgap adjustability. In pursuit of enhancing BCN's photocatalytic capabilities, we introduce an innovative approach to incorporate Bi2O3 nanoparticles onto BCN's surface through a thermal condensation process. The assessment of photocatalytic activity involved the degradation of both non-dye and dye compounds (acetaminophen, malachite green, and reactive blue) under UV–visible light irradiation. Our findings reveal that the Bi2O3/BCN (BiBCN) composites exhibit significantly improved photocatalytic activity compared to individual BCN or Bi2O3. Notably, the 5%BiBCN photocatalyst excels, achieving removal rates of 80.88 % for ACE, 98.6 % for MG, and 97.7 % for RB within 120 min under UV–Vis light exposure. Characterization unveils that the composite photocatalysts enhance the separation of photogenerated carriers, primarily attributed to the formation of heterojunctions. Our proposed mechanism underscores the synergy of increased specific surface area and the heterojunction formed by the interaction between Bi2O3 and TCN in enhancing photocatalytic performance. Altogether, this study sheds light on the promising potential of BCN-based heterojunction photocatalysts for efficient water depollution.

Growth of CuS nanowire on copper mesh for efficient solar-driven water evaporation and wastewater purification

This study proposed a multifunctional material, CuS nanowire, grown on a copper mesh (CM), for application in wastewater purification. CuS/CM could rapidly evaporate and collect water under solar irradiation. CuS nanowires were successfully synthesized on CM through a liquid–solid reaction at room temperature, followed by sulfidation. Water evaporation experiments conducted using meshes suspended in water to determine the most efficient configuration revealed that CuS/CM was the most efficient material. Owing to the localized surface plasmon resonance induced by oxygen vacancies, CuS/CM exhibited a high water evaporation rate (4.0523 kg·m-2h−1 @ 3 sun) and energy conversion efficiency (96.1 %) in Structure A with a vertical length of 4 cm under 3 sun irradiation. To evaluate its effectiveness in wastewater treatment, CuS/CM was used to evaporate and collect methylene blue (MB)-contaminated water at rates of 1.5747 and 0.8624 kg·m-2h−1. Furthermore, CuS/CM demonstrated photocatalytic activity during MB degradation. Under xenon lamp illumination for 6 h, CuS/CM exhibited a 73 % degradation efficiency for MB, indicating its photocatalytic properties. CuS/CM effectively purify dyeing wastewater due to their fast water evaporation rate and the photocatalytic capability of CuS, making them promising for wastewater treatment and desalination applications.

Fabrication of MXene-derived TiO2/Ti3C2 integrated with a ZnS heterostructure and their synergistic effect on the enhanced photocatalytic degradation of tetracycline

Developing innovative photocatalysts for the efficient degradation of pharmaceutical pollutants is crucial in environmental remediation. In this study, we investigate the synthesis of TiO2 nanosheets derived from MXene, specifically integrated onto highly conductive Ti3C2 MXene, and subsequently combined with zinc sulfide (ZnS) to form a heterojunction. This integration process is accomplished using a hydrothermal approach followed by a self-assembly method. We aim to assess the effectiveness of this integrated system in enhancing the photocatalytic degradation of tetracycline (TC). TiO2/Ti3C2 (TT) synthesized in situ exhibits high-energy lattice facets (001) of TiO2 nanosheets, thereby contributing to an exclusive heterojunction within the TiO2/Ti3C2/ZnS (ZTT) heterostructure. The loading of ZnS nanoparticles significantly increases the surface area with a narrow band gap, enhancing the potential for light emission within the visible region. Consequently, ZnS synergistically affects the ZTTx (where x = wt% of ZnS on TT) heterostructure matrix, notably promoting the separation and transfer abilities of the photogenerated carriers. The ZTT5 heterostructure exhibits remarkable adsorption and photoreduction efficiencies, achieving a 97.1 % TC removal in 60 min under UV light. Moreover, under simulated solar light, the ZTT5 heterostructure exhibits an impressive TC removal rate of ∼93.8 % in 90 min. These results highlight the effective performance of the ZTT5 heterojunction catalyst in facilitating photogenerated charge carriers, leading to improved photocatalytic capabilities. Furthermore, the band structure and density of states of TiO2 (101), Ti3C2 (002), and ZnS (111) were investigated using density functional theory. In addition, a photoreduction mechanism was proposed for TC, involving the transfer of electrons from TiO2 to the MXene surface. After the transfer, the electrons react with O2 to generate •O2−, attributed to the high electron mobility of MXene. The results of this study emphasize the significant potential of the ZTT5 heterostructure for efficiently degrading pharmaceutical pollutants from wastewater.

Simultaneous photocatalytic degradation and SERS detection of tetracycline with self-sustainable and recyclable ternary PI/TiO2/Ag flexible microfibers

Facile and efficient photocatalysts using sunlight, as well as fast and sensitive surface-enhanced Raman spectroscopy (SERS) substrates, are urgently needed for practical degradation of tetracycline (TC). To meet these requirements, a new paradigm for PI/TiO2/Ag organic‒inorganic ternary flexible microfibers based on semiconducting titanium dioxide (TiO2), the noble metal silver (Ag) and the conjugated polymer polyimide (PI) was developed by engineering a simple method. Under sunlight, the photocatalytic characteristics of the PI/TiO2/Ag flexible microfibers containing varying amounts of Ag quantum dots (QDs) were evaluated with photocatalytic degradation of TC in aqueous solution. The results demonstrated that the amount of Ag affected the photocatalytic activity. Among the tested samples, PI/TiO2/Ag-0.07 (93.1%) exhibited a higher photocatalytic degradation rate than PI/TiO2 (25.7%), PI/TiO2/Ag-0.05 (77.7%), and PI/TiO2/Ag-0.09 (63.3%). This observation and evaluation conducted in the present work strongly indicated a charge transfer mechanism. Moreover, the PI/TiO2/Ag-0.07 flexible microfibers exhibited highly sensitive SERS detection, as demonstrated by the observation of the Raman peaks for TC even at an extremely low concentration of 10–10 moles per liter. The excellent photocatalytic performance and SERS detection capability of the PI/TiO2/Ag flexible microfibers arose from the Schottky barrier formed between Ag and TiO2 and also from the outstanding plasmonic resonance and visible light absorptivity of Ag, along with immobilization by the PI. The successful synthesis of PI/TiO2/Ag flexible microfibers holds significant promise for sensitive detection and efficient photocatalytic degradation of antibiotics.

Study of double perovskite materials RbX2Y3O10 (X[dbnd]Mg, Ca, Y[dbnd]Ti, Zr) for photocatalytic applications: A DFT insights

The double perovskites have excellent photocatalytic capabilities and could be used for water splitting purposes. Herein, we used density functional theory (DFT) computations to inspect the compound's characteristics. Generalized gradient approximation (GGA)-Perdew-Burke-Ernzerhof (PBE) exchange-correlation functional with compounds space group 123 (p4/mmm) are used for investigations. According to the findings, The structural characteristics show that these compounds have a tetragonal nature (a = b≠c) with 16 atoms. The electronic band structures indicate that all compounds have a semiconductor nature with an indirect energy bandgap Eg of 2.25 eV, 2.92 eV, and 2.31 eV for RbCa2Ti3O10, RbMg2Zr3O10, and RbMg2Ti3O10, respectively. According to analyses of the Mulliken atomic (MA) populations, every chemical has complex bonding with both covalent and ionic characteristics. The elastic characteristics of the perovskite revealed that it is elastically anisotropic and mechanically stable. The calculated values of Pugh's (1.48, 1.91, 4.42) and Poisson's (0.22, 0.28, 0.39) ratios indicate that the substances RbCa2Ti3O10 and RbMg2(Zr/Ti)3O10 under study are brittle and ductile by nature. As a result, we anticipate that these compounds are valuable in the growth of high-performance photocatalytic devices for water splitting for various applications like producing hydrogen and oxygen.

CdBi2S4-Decorated Aminated Polyacrylonitrile Nanofiber for Photocatalytic Treatment of Cr(VI) and Tetracycline Wastewater.

The significant threat posed by the high toxicity of heavy metals and antibiotics in water pollutants has prompted a growing emphasis on the development of highly efficient removal methods for these pollutants. In this paper, flexible electrospinning polyacrylonitrile (PAN) nanofiber-supported CdBi2S4 was synthesized via a hydrothermal method, followed by amination treatment with diethylenetriamine (DETA). The as-prepared CdBi2S4/NH2-PAN nanofiber, enriched with sulfur vacancies, demonstrated outstanding visible-light trapping ability and a suitable band gap, leading to efficient separation and transport of photogenerated carriers, ultimately resulting in exceptional photocatalytic capability. The optimal 3-CdBi2S4/NH2-PAN nanofiber achieved impressive reduction rates of 92.26% for Cr(VI) and 96.45% for tetracycline hydrochloride (TCH) within 120 min, which were much higher than those for CdS/NH2-PAN, Bi2S3/NH2-PAN, and CdBi2S4/PAN nanofibers. After five cycles, the removal rate of the CdBi2S4/NH2-PAN nanofiber consistently remained above 90%. Their ease of separation and recovery from the application environment contributes to their practicality. Additionally, compared with conventional suspended particle catalyzers, the composite nanofiber exhibited remarkable flexibility and self-supporting properties.