Visible Light Responsive Photocatalyst Research Articles

Ornamental kale-like ZnO nanostructure/CdS nanoparticle/MoS2 nanosheet ternary heterojunctions for efficient charge transfer and robust visible-light photocatalytic performance

Photocatalytic technology utilizing Z-scheme protocol offers a promising method for eliminating contaminants from water in the presence of visible light. In this work, by combining hydrothermal and chemical deposition methods, a new type of ornamental kale-like ZnO nanostructure/CdS nanoparticle/MoS2 nanosheet (ZCM) ternary photocatalyst was fabricated, which exhibits excellent visible light photocatalytic performance. A small amount of MoS2 nanosheets significantly improves the activity of the double Z-scheme ZCM photocatalyst. As compared to ZnO/CdS, the pseudo-first-order kinetic constant of the best ZCM sample for degradation of rhodamine B is 2.2 times higher. In light of free radical capture and PL results, a Z-scheme transport mechanism was revealed to increase the carrier separation rate and maintain strong redox stability. This study provides a solid basis for designing Z-scheme photocatalysts and developing a range of visible light-responsive photocatalysts.

Pt/MWCNT/ZnTiO3 nanocomposite: An efficient, reusable visible-light responsive photocatalyst for degradation of Thiamethoxam insecticide and methylene blue in aqueous phase

Surface modification and bandgap manipulation of ZnTiO3 are proposed to significantly enhance its photocatalytic activity by reducing charge carrier recombination. In this study, we developed a novel ternary photocatalyst by incorporating Pt nanoparticles (Pt NPs), multiwall carbon nanotubes (MWCNT) and ZnTiO3 nanostructures. The synthesis of ZnTiO3 was carried out using the sol-gel methodology, while the Pt@MWCNT/ZnTiO3 photocatalyst was fabricated through ultrasonication and photo-reduction routes. X-ray diffraction (XRD) analysis confirmed the formation of rhombohedral ZnTiO3, and transmission electron microscopy (TEM) examination revealed a well-dispersed arrangement of Pt NPs on the MWCNT/ZnTiO3 nanocomposite. The successful development of the Pt@MWCNT/ZnTiO3 photocatalyst was affirmed through Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray spectroscopy (EDS) examinations. A reduction in the bandgap energy was observed with the modification of ZnTiO3 to the ternary Pt@MWCNT/ZnTiO3. The newly developed Pt@MWCNT/ZnTiO3 photocatalyst demonstrated exceptional effectiveness, achieving a remarkable 92.62 % removal of the insecticide derivative thiamethoxam (TXM) in just 40 min under visible light. This represents 2.12 times greater efficiency than pure ZnTiO3. Moreover, the Pt@MWCNT/ZnTiO3 nanostructure exhibited remarkable efficacy in the degradation of methylene blue (MB) dye, eliminating its complex structure in just 12 min, with excellent reusability. The outstanding photodegradation capabilities of Pt@MWCNT/ZnTiO3 can be attributed to the presence of highly ordered mesoporous ZnTiO3, an increase in surface area, a favorable bandgap, and improved visible light absorption. Additionally, this Pt@MWCNT/ZnTiO3 photocatalyst demonstrated effective mitigation of charge carrier recombination. The highly efficient nature of the developed ternary Pt@MWCNT/ZnTiO3 photocatalyst holds substantial promise for widespread applications in environmental remediation activities.

Preparation of direct Z-scheme heterojunction la-doped Bi2WO6/CdS with enhanced visible light absorption and its photocatalytic degradation of antibiotics

In this paper, a novel direct Z-scheme heterojunction La-Bi2WO6/CdS composed of 3-dimensional flower-like Bi2WO6 and hexagonally stacked succulent CdS was successfully designed and synthesized. The morphology, optical properties, element valence and crystal structure of the catalysts were systematically characterized. When the dosage of LBC-40 was 1.0 g/L, the degradation rate of oxytetracycline (OTC, 20 mg/L, pH = 6) was 85.28 %, under low visible light illumination (65 W energy saving lamp) for 120 min and the reaction kinetic constant (0.01336 min−1) was 2.50 and 1.56 times that of pure Bi2WO6 and La-Bi2WO6, respectively. Moreover, La-Bi2WO6/CdS showed good photocatalytic activity for other single antibiotics, mixed antibiotics and antibiotics from different water sources. The photocatalytic activity only decreased by 7.69 % after 3 cycles. Furthermore, the possible photocatalytic degradation pathway and photocatalytic mechanism of OTC were proposed. The excellent photocatalytic performance of La-Bi2WO6/CdS is for that the doping of La3+ and the construction of direct Z-scheme heterojunction enhances the visible light absorption capacity and separation efficiency of photogenerated electron-hole pairs. This paper reports a new method, which can provide a reference for the design and development of visible light responsive photocatalysts with excellent photocatalytic properties.

Facile fabrication of Z-scheme ZnO/MoO3 heterojunction as an excellent visible-light responsive photocatalyst for the degradation of rhodamine B and alizarin yellow dyes

xZnO-(1-x) MoO3(x = 0.0,0.1,0.3,0.5,0.7) nanocomposite materials have been efficiently fabricated by the facile hydrothermal method to enhance the photocatalytic activities for the environmental applications. The fabricated samples were characterized via XRD, SEM, EDX, XPS, UV–Visible spectroscopy, PL and FTIR analysis. The 5% ZnO-M nanocomposite material exhibits reduced band gab energy and superior photocatalytic activity for rhodamine B (RhB) and alizarin yellow (AY) dyes degradation of 94% and 81% within 120 min under visible light irradiance. Our reported study reveals that the 5% ZnO-M photocatalyst is extremely stable and reusable for more than five reaction of cycles. The photocatalytic enactment of the 5% ZnO-M composite was mostly endorsed due to Z-scheme photocatalysts, higher visible light adsorption on the surface morphology, improved charge separation/transfer, and decreased recombination rate. This study may provide new ideas for developing effective, innovative Z-scheme heterojunction photocatalysts and encouraging their extensive application for the degradation of dyes from wastewater.

Decoration of 0D Bi3NbO7 nanoparticles onto 2D BiOIO3 nanosheets as visible-light responsive S-scheme photocatalyst for photo-oxidation of antibiotics in wastewater

In this work, a new S-type hybrid composed of 2D BiOIO3 and 0D Bi3NbO7 was proposed and hybridized by a facile self-assembly strategy. The developed nanomaterials were characterized and identified by a series of sophisticated analyses, like XRD, SEM, EIS, XPS, PL, UPS, EDS, BET, M-S, TEM, HRTEM, and DRS. The photocatalytic behavior of BiOIO3/Bi3NbO7 was examined and optimized against amoxicillin (AMX) and other types of antibiotics under a variety of environmental conditions, such as visible light (150 W LED), direct sunlight, pH (3–11), catalyst dosages (20–80 mg), humic acid (0–24 mg/L), AMX concentration (10–40 mg/L), and different inorganic ions (0.05 M). The optimized BiOIO3/Bi3NbO7 hybrid attained exceptional AMX degradation activity (96.5%) under visible light (60 min), with a reaction constant of up to 0.04559 min−1, exceeding bare BiOIO3 and Bi3NbO7 by 5.57 and 5.3 folds, respectively. The obtained BiOIO3/Bi3NbO7 hybrid unclosed expanded light utilization behavior compared with neat catalysts, which originates from the powerful incorporation between BiOIO3 and Bi3NbO7 in the S-type system. The radical investigations confirmed the superiority of BiOIO3/Bi3NbO7 in generating both •OH and •O2− during the photoreaction. The novel Bi3NbO7-based heterojunction afforded robust photostability in five treatment cycles and simple charge transfer activity in the S-type route, boosting the photo-mechanism for antibiotic degradation in an efficient manner. The building of the S-scheme heterojunction between BiOIO3 and Bi3NbO7 stimulates the utilization of holes by the recombination process and promotes the overall stability of the composite. Our study introduces a new class of semiconductor heterojunctions that may contribute to the development potential of the photocatalysis sector in wastewater treatment.

Microwave-hydrothermal synthesis of F and Fe co-doped CeO2 photocatalysts for efficient removal of 2,4,6-TCP under visible light

In recent years, the massive use and migration of chlorine-containing organics into the environment potentially threaten the natural environment and human health. Advanced oxidation technology based on photocatalysts is a promising approach for the degradation of chlorine-containing organic pollutants, but the development of stable and efficient photocatalysts remains a challenge. In this study, a new visible light-responsive photocatalyst based on F and Fe co-doped CeO2 (FeFC) was synthesized by making full use of overall heating characteristic of microwaves. XRD, SEM-EDS, XPS, BET and DRS results showed that F and Fe was successfully co-doped into CeO2 with increased BET surface and narrowed band gap. The degradation experiments showed that the co-doping of F and Fe significantly enhanced the photocatalytic activity of CeO2 by enhancing visible light absorption and charge carriers separation. Moreover, CeO2 material with both F and Fe doping of 10 % (FeFC-10) showed the highest removal (99.8%) and de-chlorination (89%) rates of 2,4,6-TCP within 4h, which was 3.8 and 3.2 times higher than that of pure CeO2 prepared by microwave and muffle furnace, respectively. Free radical scavenging experiments and electron paramagnetic resonance (EPR) tests finally demonstrated that the h+ and ·OH were the active species that played a catalytic redox role in this reaction system. Furthermore, the degradation intermediates of 2,4,6-TCP were identified by LC-MS and the possible reaction pathways were suggested. In this paper, the photocatalyst (FeFC-10) synthesized by microwave-hydrothermal method could not only save time and energy, but also efficiently degrade 2,4,6-TCP, which could provide the theory and practice for protecting water environment contaminated by chlorine-containing organics through the synthesis of CeO2 based photocatalysts.

Visible-light responsive BiVO4 nanocompositions: Enhanced photocatalytic, electrical and optical performance through Ni and Ni/Co doping

The pronounced light sensitivity of BiVO4 has garnered significant attention, establishing it as a visible light-responsive photocatalyst. This study was focused on enhancing the optical, dielectric constant properties, and photocatalytic activity of BiVO4 compositions. By employing a modified combustion method, pure BiVO4, Ni-mono-doped (BiNi0.02V0.98VO4), and Ni/Co-bi-doped (BiCo0.02Ni0.02V0.96VO4) were synthesized. X-ray diffraction (XRD) analysis validated the formation of a monoclinic BiVO4 phase. The incorporation of Ni2+ and Co2+ ions into the BiVO4 lattice was supported by variations in the lattice parameters, volume expansion and increased average crystallite size. Morphological investigation via scanning electron microscopy (SEM-EDAX) confirmed the purity of the synthesized nanocompositions and unveiled distinctive rod-like and needle-like particle shapes in BiNi0.02Co0.02V0.96VO4, with an aspect ratio of 0.07–0.1, indicating potential benefits for efficient charge separation in photocatalysis. Optical examination highlighted redshifts in band gap energy (2.36 eV) due to both Ni and (Co, Ni) co-doping, leading to direct band gaps of 2.34 eV and 2.32 eV, respectively. High refractive index values exceeding 2.5, conducive to optical applications, were observed across all samples. Through Ni and Ni/Co doping process, a notable enhancement in conductivity emerged, particularly within the low-frequency domain. The co-doping of Ni and Co demonstrated elevated relative permittivity (εʹ) values exclusively within the low-frequency span, up to 100 Hz. In contrast, the Ni-mono-doping interestingly disclosed an enhancement in (εʹ) across all frequency ranges. Photocatalytic results demonstrated heightened degradation activity in doped samples, with the BiNi0.02Co0.02V0.96VO4, sample exhibiting the highest rate, achieving 88 % degradation efficiency in 180 min. This exceptional performance can be attributed to its visible-light-responsive band gap, increased electron-hole trapping sites, and distinct morphology.

Modulating Narrow Bandgap in a Diacetylene Functionalized Woven Covalent Organic Framework as a Visible Light Responsive Photocatalyst.

Woven covalent organic frameworks (COF) possess three dimensional frameworks with spatially isolated Cu(I) centers and have promising optoelectronic properties because of metal to ligand charge transfer (MLCT). However, despite their potential, woven COFs have not yet been investigated as photocatalysts. In this study, we developed a new woven COF, Cu-PhenBDA-COF, functionalized with diacetylene bonds. Cu-PhenBDA-COF was fully characterized, and the optoelectronic and photocatalytic properties were compared to previously reported Cu-COF-505. The diacetylene bonds of the linker positively impacted the optoelectronic properties of Cu-PhenBDA-COF and resulted in a narrower band gap and better charge separation efficiency. When the Cu(I) center was removed from both woven COFs, the absorption edge was blue shifted, resulting in a wider band gap, and there was a considerable decrease in the charge separation efficiency, underscoring the pivotal role of MLCT. This trend was reflected in the photocatalytic activity of the woven COFs toward the degradation of sulfamethoxazole in water, where the highest reaction rate constant (k app ) was recorded for the metallated diacetylene functionalized woven COF, Cu-PhenBDA-COF.

Degradation of multiple xanthates using highly efficient visible light-responsive BiOBr-TiO2 composite photocatalysts

BiOBr-TiO2 (BT) composite photocatalysts were synthesized by using a two-step method including hydrothermal synthesis and water-bath precipitation. The microstructural characterization analysis proved that high-crystallinity and high-purity binary BT materials were achieved without by-products. TiO2 nanoparticles with a diameter of approximately 15 nm were decorated on multi-layered BiOBr nanosheets. The results showed that BT had highly-improved adsorption capacity and photocatalytic efficiency in comparison to pristine BiOBr and TiO2. The reaction rate constant of the optimal BT-2 composite photocatalysts for the degradation of 20 mg/L sodium ethyl-xanthate could reach 0.06496 min−1, which was 2.7 and 40.3 times than pure BiOBr and TiO2, respectively. The free radical scavenger test demonstrated that photogenerated holes were the main active species in the photocatalytic degradation reaction process. A possible degradation pathway for SEX molecules was provided through the interaction of visible light and BT-2 photocatalyst. The as-prepared BT materials can be used as efficient photocatalysts to completely degrade various types of xanthates under visible light.

Efficient visible light performance of MoS2QDs/TiO2 hollow sphere photocatalysts for the degradation of dyes and antibiotics

In this paper, molybdenum disulfide quantum dots (MoS2QDs) and TiO2 nanoparticles were used as visible light-responsive photocatalysts. The intensity of the bandgap photoluminescence of quantum dots was reduced after combining MoS2QDs with TiO2. This indicates that the photoexcited electrons in MoS2QDs are easily transferred to TiO2. The combination of MoS2QDs and TiO2 inhibits the recombination of charges and the complexation of photogenerated carriers, thus improving the degradation efficiency of dyes and antibiotics in the photocatalytic process. The cycling results showed that the MoS2QDs/TiO2 composites had good cycling stability. After five cycles of experiments, the composites still maintained similar degradation activity. Finally, a possible mechanism of the photocatalytic reaction of MoS2QDs/TiO2 is proposed. The charge generation and electron-hole separation capability of MoS2QDs/TiO2 in a wide spectral range can effectively separate photogenerated electron-hole pairs and maintain its high redox capability. It provides a broad prospect for composite materials to improve photocatalytic activity in different fields and offers many new possibilities for solar energy collection systems.

Photo-Fenton degradation of tetracycline antibiotic over MIL-101(Cr)/FeOOH nanocomposite as stable and efficient visible light responsive photocatalyst.

Designing an inexpensive, easily synthesized, stable and efficient photocatalyst is a major challenge in photocatalysis area, especially when photo-reaction is performed in aquatic medium to degrade organic pollutants. To this aim, nano-sized MIL-101(Cr) (MIL = Materials Institute Lavoisier), as chemically tolerant metal-organic framework (MOF), was simply prepared via HF-free hydrothermal synthesis procedure. In order to decorate amorphous FeOOH quantum dots (QDs) on the surface of this MOF, various amounts of FeOOH QDs (i.e., 5, 10, 15 and 20 wt%) were synthesized in the presence of MIL-101(Cr) to prepare MIL-101(Cr)/FeOOH(x%) nanocomposites. Decoration of such iron oxide quantum dots on the surface of MIL-101(Cr) and investigation of its activity in photo-Fenton degradation of tetracycline (TC) antibiotic is reported here for the first time. Among the synthesized nanocomposites, MIL-101(Cr)/FeOOH(15%) demonstrated superior photo-Fenton activity in degradation of TC (80%) at short reaction time under optimum reaction condition using the energy-efficient white LED lamps as visible light source. It was observed that the synergy between any component of this photo-Fenton system such as nanocomposite, hydrogen peroxide and visible light is the main reason for enhancement of TC removal over time. Also, neither MIL-101(Cr) nor FeOOH QDs exhibited poor degradation efficiency, which implies the positive role of the coupling of these materials. Furthermore, the stability and recoverability of MIL-101(Cr)/FeOOH(15%) nanocomposite was investigated in four photo-Fenton cycles, which no significant decrease in TC degradation performance was observed.

Unraveling the synergy of interface engineering α-MnO2/Bi2WO6 heterostructures and defective active sites for superdurable photocatalysis: Mechanistic insights into charge separation/transfer

The construction of visible-light-driven hybrid heterostructure photocatalysts is of great significance for environmental remediation, although the utilization of strong visible-light response photocatalysts with high efficiency and stability remains a major challenge. On the other hand, defect engineering is an excellent way to introduce metal cation vacancies in materials, thereby ensuing in highly enhanced catalytic performance. Inspired by this, we effectively constructed a built-in interface α-MnO2/Bi2WO6 heterostructure with abundant intimate interfaces and defective Mn3+/Mn4+ active sites for photocatalytic tetracycline hydrochloride (TC-HCl), hexavalent chromium Cr6+ reduction, and Escherichia coli (E. coli) inactivation. The experimental results, such as the active species test and X-ray photoelectron spectroscopy, indicated that the defective sites Mn3+/Mn4+, surface oxygen vacancies, and Bi(3+x)+ boosted the visible light absorption, and highly enhanced the photoinduced charge separation/transfer. Furthermore, experimental and DFT calculations reveal the high charge density at the built-in interface heterostructure and the Z-scheme charge transfer mechanism during the photocatalytic process. The results further reveal that O2− and 1O2 are the main reactive active species contributing to the photocatalytic reaction. The exceptional TC-HCl decomposition activity of the α-MnO2/Bi2WO6 heterostructure (97.56%, 2.31, and 2.04 times higher than bulk), enhanced reaction kinetics (Kapp = 0.041 min−1, 6.4, and 5.2 times higher than bulk), removal rate of 80.3%, Cr6+ reduction to Cr3+ (98.56%, Kapp = 0.0599 min−1), and almost 100% bacterial inactivation compared to bulk α-MnO2 (42.22%) and Bi2WO6 (47.76%), were mainly due to the enhanced charge separation/transfer at the built-in interface and high charge density. This study opens new horizons for constructing Z-scheme MnO-based interface heterostructures with abundant defect sites for exceptional photocatalytic applications.

Facile synthesis of Pd nanoparticles dispersed polypyrrole-carbon black/NiO nanocomposite with enhanced photocatalytic degradation of colored and colorless organic pollutants

Creation and designing of efficient visible-light responsive photocatalysts requires highly precise and extremely determined efforts in order to obtain material with promising properties and efficient transfer of charge carriers. In this work, we aim to develop and manufacture a distinct visible light photocatalyst consisting of NiO nanostructures, polypyrrole doped carbon black (PPyC) and Pd nanoparticles for wastewater treatment. The Pd NPs and PPyC doped NiO trio photocatalyst was developed via simple ultrasonication and photoreduction methods. XRD analysis showed that NiO has crystalline face centered cubic structure while the successful development of ternary photocatalyst was smoothly confirmed by X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared (FTIR) studies. Transmission electron microscopy (TEM) images showed that NiO possessed fine irregular shape particles with size ranging from 20 to 50 nm grown abundantly in huge density, while the PPyC exhibited beads shape structures interconnected with each other giving chain like appearance. The diffuse reflectance UV–vis spectra showed red shift and lowering in bandgap upon Pd and PPyC doping. The newly produced Pd-PPyC@NiO photocatalyst has been exploited for the photocatalytic removal of colorless insecticide imidacloprid and colored methylene blue (MB) dye under visible light irradiation. The newly created Pd-PPyC@NiO photocatalyst removed 96.0% of imidacloprid just in 20 min representing ⁓ 3 times more efficient than bare NiO. Furthermore, Pd-PPyC@NiO photocatalyst was exceptionally well towards the destruction of MB under same visible light source, indicating its potential use in photocatalysis.

The Al2XS4 (X = Cd, Zn and Hg) for promising photocatalytic performance: First-principles investigations

H2 is one of the lightest gases, non-toxic, odourless, with a combustion product of water and a calorific value 2.8 times that of gasoline, and is therefore considered to be one of the most desirable sources of clean energy. The electronic structure and optical properties of three structures of intrinsic Al2XS4 (X = Cd, Zn and Hg) have been investigated using the GGA-PBE method. The calculated valence-conduction band positions indicate that all three structures satisfy the conditions for hydrogen production by hydrolysis.The high absorption coefficient of Al2HgS4 in the visible region implies that Al2HgS4 can efficiently utilise solar energy, suggesting that this structure is a potential visible light responsive semiconductor photocatalyst.

Gold and nanosized titanium carbide MXene heterozygotes as highly efficient visible-light responsive photocatalysts for ammonia synthesis

Utilizing sunlight to drive photocatalytic conversion of N2 into NH3 is a promising approach to mitigate the substantial energy consumption associated with the Haber–Bosch process. However, significant challenges remain unaddressed before the practical application of photocatalysts can be realized. Various materials and nanoscale design strategies have been investigated with the aim of achieving a high quantum yield. Among these, MXenes can be a promising photocatalyst for NH3 synthesis due to its excellent N2 fixation performance. In this work, we investigate the use of nanosized Ti3C2 MXene and plasmonic gold nanoparticles (AuNPs) for NH3 synthesis with visible light. We observed a formation of heterozygote structures between AuNPs and reduced nanosized Ti3C2, resulting in a 4.4-fold increase in the photocatalytic activity compared to that of reported microscale Ti3C2 with AuNPs nanocomposites. The improved photocatalytic performance is originated from the enhanced light absorption of AuNPs, and the efficient N2 fixation by the nanosized Ti3C2 MXene with a reduced chemical state, which is demonstrated experimentally with gas chromatographic analysis. The various experimental conditions involving catalysts, concentration, pH, and scavengers are investigated, the highest photocatalytic performance was achieved with the heterozygote structures of AuNPs and nanosized Ti3C2 MXene under optimized conditions, and yielding 5334 μmol gcat−1 h−1 of ammonia, an amount at least 13-fold higher than that of previously developed photocatalysts.

Band Gap Engineering of MOF-801 via Loading of γ-Fe2O3 Quantum Dots Inside It as a Visible Light-Responsive Photocatalyst for Degradation of Acid Orange 7

Band Gap Engineering of MOF-801 via Loading of γ-Fe₂O₃ Quantum Dots Inside It as a Visible Light-Responsive Photocatalyst for Degradation of Acid Orange 7

Boosting photocatalytic hydrogen evolution: Electronic redistribution of ZnIn2S4 nanosheets via halogen ion doping

Designing a visible light responsive photocatalyst is the path to enhancing the efficiency of solar power for hydrogen generation. Herein, we provide a method that makes use of doping I atoms to regulate the surface state of ZnIn2S4 (ZIS) nanosheets and enhance surface reaction processes in order to increase photocatalytic performance. The optimized I-ZIS photocatalyst achieves a high hydrogen yield of 4.73 mmol g−1 h−1, which is 29.56 folds more than pure ZIS. Experiment measurements and first-principles simulations demonstrate that the shallow energy level formed by I doping optimizes the local electronic distribution of ZIS, strengthens the electrons’ delocalization capacity of S atoms for high electrical conductivity, and inhibits the regrouping of photo-generated electron and hole pairs, leading to an increase in the photocatalytic activity of the I-ZIS photocatalyst for hydrogen evolution. The research presents a novel viewpoint that a shallow energy level enhances the ability to separate photo-excited electron and hole pairs and accelerates the rate of hydrogen production.

Theoretical insights on geometrical, mechanical, electronic, thermodynamic and photocatalytic characteristics of RaTiO3 compound: A DFT investigation

Using Ab-initio simulations based on density functional theory (DFT), we have comprehensively examined the geometrical, elastic, electronic, mechanical, thermodynamic and optical features of the RaTiO3 crystal. In beginning, by using the popular generalized gradient approximation (GGA) which is based on the perdew-burke-ernzerhof (PBE) and B3LYP functional techniques, the bandgap energies of RaTiO3 crystal have been calculated to be 1.56 eV and 3.28 eV respectively. By simulating RaTiO3's the density of state analysis and partial electronic density of state analysis, the nature of Ra, Ti, and O atoms orbitals were then ascertained. The Mulliken population charge has been calculated to clarify the bonding properties of RaTiO3. RaTiO3 crystal is mechanically stable, ductile nature and elastically anisotropic and retained a stable thermal state of this crystal. The reflectivity, conductivity, dielectric function, loss function, refractive index (both real and imaginary), and absorption coefficient associated with energy and wavelength of RaTiO3 crystal are carefully investigated. In both the PBE and B3LYP methods demonstrated that our RaTiO3 crystals significantly absorbed incoming light in the visible and ultraviolet regions. Finally, it is found that the crystals have exceptional photocatalytic qualities, making it stronger contenders for visible light response photo-catalysts.

A "Test-to-Treat" Pad for Real-Time Visual Monitoring of Bacterial Infection and On-Site Performing Smart Therapy Strategies.

Skin infections are major threats to human health, causing ∼500 incidences per 10 000 person-year. In patients with diabetes mellitus, particularly, skin infections are often accompanied by a slow healing process, amputation, and even death. Timely diagnosis of skin infection strains and on-site therapy are vital in human health and safety. Herein, a double-layered "test-to-treat" pad is developed for the visual monitoring and selective treatment of drug-sensitive (DS)/drug-resistant (DR) bacterial infections. The inner layer (using carrageenan hydrogel as a scaffold) is loaded with bacteria indicators and an acid-responsive drug (Fe-carbenicillin frameworks) for infection detection and DS bacteria inactivation. The outer layer is a mechanoluminescence material (ML, CaZnOS:Mn2+) and visible-light responsive photocatalyst (Pt@TiO2) incorporated elastic polydimethylsiloxane (PDMS). On the basis of the colorimetric sensing result (yellow for DS-bacterial infection and red for DR-bacterial infection), a suitable antibacterial strategy is guided and then performed. Two available bactericidal routes provided by double pad layers reflect the advantage. The controllable and effective killing of DR bacteria is realized by in situ generated reactive oxygen species (ROSs) from the combination of Pt@TiO2 and ML under mechanical force, avoiding physical light sources and alleviating off-target side effects of ROS in biomedical therapy. As a proof-of-concept, the "test-to-treat" pad is applied as a wearable wound dressing for sensing and selectively dealing with DS/DR bacterial infections in vitro and in vivo. This multifunctional design effectively reduces antibiotic abuse and accelerates wound healing, providing an innovative and promising Band-Aid strategy in point-of-care diagnosis and therapy.

Novel ultrafiltration membrane fabricated using nanofiber layer as integral filler: Taking PAN and C3N4 as example

This study introduces a novel ultrafiltration (UF) membrane, called NFFM, which utilizes a nanofiber (NF) layer as an integral filler during the phase inversion process. The photoactive NFFM was prepared using photoactive PAN-C3N4 (PCN) NF, which is made using C3N4 nanosheets as a visible light responsive photocatalyst with a loading ratio of up to 20%. NFFM membranes made using PAN NF, hydrophilic modified PAN-C3N4 (HPC) NF as filler, and PAN-C3N4 blend membrane were also prepared for comparison. NFFMs showed special morphologies, such as porous surfaces, selective layer located at the internal interface in cross-section, diverse pore sizes and pore size distribution, which are different from that of the traditional blend membrane made with the same ratio of components. Because the dissolving of NF layer into the casting solution changes the composition, polymer distribution, and property of the casting solution, thus change the membrane property. Thickness, composition and surface states of NF Layer can influence its dissolution process. Membrane filled with PCN NF (NFFM-PCN) showed a smaller pore size than membrane filled with HPC (NFFM-HPC), due to the low solubility of HPC. Moreover, a longer contacting time can cause the casting solution penetrate into the surface of the HPC layer, leading to a smooth surface. Finally, dye rejection and photoactivity test showed that NFFM-PCN showed better dye rejection property and photoactivity than other membranes, despite the lower photoactivity of C3N4 due to the coverage effect of PAN. Overall, this primitive study provides a new method for preparing a new type of membrane for some potential applications.