Photocatalytic Applications Research Articles

An investigation of Z-scheme homojunction BiVO4 photocatalysts for efficient green removal of ammonia nitrogen

With in-depth research on photocatalytic pollution removal, homojunction semiconductors stand out for their simple structure and stability. However, their similar energy levels result in lower photocatalytic activity compared to heterojunctions, limiting their applications in photocatalysis. Therefore, in this study, homojunction BiVO4 photocatalysts with staggered energy level structures were prepared by compositing crystalline facet-modified BiVO4 with oxygen vacancy-modified BiVO4 and used for the removal of ammonia nitrogen from water. The homojunction BiVO4 photocatalysts were successfully prepared, and the good photocatalytic performance of OBVV-2 was confirmed by several characterizations and tests, with the ammonia nitrogen removal rate of 84.3 % under visible light, of which 93.6 % was converted into harmless N2. The Z-scheme transfer mechanism was illustrated by radical capture experiments, and the repeated cycling experiments demonstrated that the homojunction photocatalysts have excellent stability. In conclusion, this study confirmed that the Z-scheme homojunction BiVO4 (OBVV-2) photocatalyst has good potential for application and provides a homojunction solution for efficient and green ammonia nitrogen removal.

Synthesis and characterization of ZnO–NiO binary nanocomposites by hydrothermal technique for gas sensing and photocatalytic applications

Inorganic photocatalytic materials exhibiting a highly efficient response to ultraviolet-visible light spectrum have become a subject of widespread global interest. Nanocomposite metal oxides, particularly Nickel Oxide (NiO) and Zinc Oxide (ZnO), have gained attention for their diverse applications in gas sensing and photocatalytic processes. In this work, ZnO-NiO (ZnO0.6NiO0.4 and ZnO0.4NiO0.6) binary nanocomposites were synthesized by hydrothermal technique. The binary nanocomposites were analyzed by UV-Visible spectrophotometer, X-ray diffraction (XRD), photoluminescence (PL), Fourier transform infrared spectrophotometer (FTIR), energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The XRD pattern revealed that the nanocomposites, the peaks of both ZnO and NiO are present indicating the presence of both crystal structures hexagonal wurtzite and cubic. The miller indices, crystallite size, microstrain and dislocation density were determined from the XRD plot. FESEM and TEM analyses showed the spherical morphology of the synthesized composites with an approximate size of 10[Formula: see text]nm. The detailed analysis of ZnO–NiO binary nanocomposite sensor characteristics in terms of sensitivity, selectivity, response and recovery time were carried out and the nanocomposites were found to be highly sensitive to CO2 100 ppm at 350∘C and Cl2 at 200∘C. The photocatalytic degradation outcome showed 52% degradation of methylene blue at 10 ppm and 90[Formula: see text]w/m2. These results suggest the potential utility of these binary nanocomposites in photocatalytic applications for the degradation of organic pollutants.

Enhanced photocatalytic oxidation of gaseous acetaldehyde using Fe-grafted ZnO nanocomposites in a continuous flow reactor

The purification of indoor air is a crucial application of photocatalysis, emphasizing the urgent need for more efficient photocatalytic systems. While photocatalytic oxidation of volatile organic compounds (VOCs) has been extensively studied in the liquid phase, effective removal of VOCs in the gaseous state in indoor air remains a significant challenge. This study focuses on the continuous gas-phase oxidation of gaseous acetaldehyde using ZnO and different weight percentage of Fe-grafted ZnO catalysts under light irradiation. The surface analysis using XPS and HR-TEM confirmed the presence of Fe(III) species, and UV–Vis-DRS analysis demonstrated a shift in the absorption edge towards the visible region. Real-time gas FTIR monitoring of acetaldehyde oxidation revealed that the 0.7% Fe(III)-grafted ZnO composite catalyst achieved a higher removal efficiency (74%) compared to bare ZnO and other Fe(III)-grafted ZnO ratios. The enhanced photocatalytic efficiency of acetaldehyde by Fe(III)-grafted ZnO supports indicated direct interfacial charge transfer (IFCT) from ZnO to Fe(III) species. Additionally, the Fe(III) cluster effectively improved the separation of electrons and holes, preventing their recombination and accelerating O₂ activation to generate O₂•⁻ radicals, which lead to high photocatalytic performance. The 0.7% Fe(III)-grafted ZnO also maintained its performance over a prolonged period of 360 min, showing excellent structural stability and durability across multiple cycles. This study highlights the possible synergistic effect of the ZnO and Fe systems, offering a new perspective on the photocatalytic decomposition of gaseous acetaldehyde in indoor environments.

Palladium based air-stable 2D penta-material’s heterostructures for water splitting applications

Heterostructures offer superior photocatalytic characteristics over their constituent counterparts due to their charge separation abilities. Here, we conduct a systematic study of a recently synthesized novel family of palladium-based pentagonal air-stable 2D monolayers, PdSe2, PdPSe, and PdPS, and their heterostructures using first-principles calculations for photocatalytic applications. Electronic band structure calculations reveal moderate bandgaps of 2.27 eV for PdSe2, 2.01 eV for PdPSe, and 2.25 eV for PdPS, indicating their suitability for photocatalytic water splitting. Moreover, to spatially separate and reduce the recombination possibility of photoinduced electron-hole pairs, we propose three van der Waals heterostructures: PdPSe/PdSe2, PdPS/PdSe2, PdPS/PdPS, with the corresponding bandgaps of 1.84 eV, 1.64 eV, and 1.65 eV, respectively. Based on work functions and the staggered band alignment of constituting monolayers, all three heterostructures are identified as type-II photocatalysts, which makes them notable photocatalyst. Additionally, band-edge potentials of PdPSe/PdSe2 and PdPS/PdSe2 confirm their suitability for overall water splitting via photocatalysis, whereas PdPS/PdPSe is suitable for oxygen evolution reactions only. The optical absorption spectra show the ability of each system to operate under a wide range of the spectrum, from visible light to high-energy (UV) regions. These characteristics make these systems valuable and attractive for photocatalytic applications.

Tunable electronic and optical properties of a type-II GaP/SiH van der Waals heterostructure as photocatalyst: A first-principles study

In this study, a novel GaP/SiH heterostructure was successfully predicted and constructed. Subsequently, an in-depth and systematic investigation was conducted to explore its structural, electronic, transport and optical properties. The calculated structural performance results revealed that the GaP/SiH heterostructure was a typical type-II van der Waals heterostructure, exhibiting excellent energy stability, mechanical stability and thermodynamic stability. In particular, the formation of the GaP/SiH heterostructure significantly reduced the bandgap of the materials to 2.24eV, and the type-II energy band arrangement effectively suppressed the recombination of photogenerated carriers. Furthermore, the biaxial and vertical strains could finely modulate the electronic structure of the GaP/SiH heterojunction. The electron mobility of the GaP/SiH heterostructure was measured to be 1573.91 cm2 V⁻1 s⁻1, indicating its superior charge carrier transport capabilities. Meanwhile, the GaP/SiH heterostructure also exhibited excellent optical absorption performance in the visible and UV region up to 2.34 × 106 cm−1. Thus, the GaP/SiH heterostructure will be a strong candidate for photocatalytic applications due to its excellent light absorption properties, electrical properties, and stability.

Ultrasonic-Assisted Conversion of Micrometer-Sized BiI3 into BiOI Nanoflakes for Photocatalytic Applications

This work describes a novel method for converting bismuth triiodide (BiI3) microplates into bismuth oxyiodide (BiOI) nanoflakes under ultrasonic irradiation. To produce BiOI nanoflakes with a high yield and high purity, the conversion process was carefully adjusted. Rapid reaction kinetics and increased mass transfer are benefits of the ultrasonic-assisted approach that result in well-defined converted BiOI nanostructures with superior characteristics. The produced BiOI nanoflakes were examined utilizing a range of analytical methods, such as Transmission Electron Microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The progress in the ultrasonic conversion process with time was monitored through diffuse reflectance spectroscopy (DRS). The outcomes demonstrated the effective conversion of BiI3 microplates into crystalline, homogeneous, high-surface-area BiOI nanoflakes. Additionally, the degradation of organic dyes (methylene blue) under ultraviolet (UV) light irradiation was used to assess the photocatalytic efficacy of the produced BiOI nanoflakes. Because of their distinct morphology and electrical structure, the BiOI nanoflakes remarkably demonstrated remarkable photocatalytic activity, outperforming traditional photocatalysts. The ability of BiOI nanoflakes to effectively separate and utilize visible light photons makes them a viable option for environmental remediation applications. This work not only shows the promise of BiOI nanoflakes for sustainable photocatalytic applications but also demonstrates a simple and scalable approach to their manufacturing. The knowledge gathered from this work opens up new avenues for investigating ultrasonic-assisted techniques for creating sophisticated nanomaterials with customized characteristics for a range of technological uses.

Dual sustainability of rGO/CuCoO2 nanocomposites with enhanced photocatalytic and antibacterial insights

New growth and photocatalytic activity of CuCoO2 and rGO/CuCoO2 nanocomposites were demonstrated for model organic pollutant (dye) and antibacterial studies. The rGO/CuCoO2 nanocomposites were designed by hydrothermal technique. CuCoO2 and rGO/CuCoO2 materials were investigated and characterized by several instrumental techniques like FT-IR spectroscopy (FT-IR), Raman spectroscopy, X-Ray diffractometer (XRD), DRS-UV Visible spectroscopy, HRTEM, FESEM analysis, Thermogravimetric analysis (TGA) and BET investigations. XRD confirmed the CuCoO2 cubic phase structure. It seems to have been evaluated for FT-IR and the Raman results were better than anything else that should be satisfied. Hence, Cu–O or Co-O (M−O−M) modes were confirmed peaks at 400 to 900 cm−1. We proposed CuCoO2 and rGO/CuCoO2 ((25/75), (50/50) & (75/25)) composite materials band gap energies at 2.8 eV to 2.0 eV. So, these results are also one of the benefits in the application area. A Sedum morganianum Burrito − Burro’s plant’s tail-like morphology was obtained in the pure CuCoO2 materials, and different weight percentages of rGO composites were also identified in FESEM-analysis as wood fungi, rods, and sheets-like structures. The rGO/CuCoO2 sheet-like morphology was confirmed by HRTEM measurements. The elemental composition of materials was investigated by EDX spectroscopy. We can prepare to suggest that the synthesis potential in the prepared matter is tbepensumed Bache formulation and much less explored, first-time declared phases and novelty of the synthetic designs, new morphologies, and bandgap energies. The synthesized rGO/CuCoO2 materials were achieved by 94 % Methylene blue (MB) dye degradation in photocatalytic applications, in which case composites were more efficient with environment-friendly when compared to CuCoO2 nanoparticles. The role of the rGO composite can be divided into three different principles such as absorbance, charge separator, and photosensitizer. This rGO material can reflect a big absorption capacity depending on the dye to rGO, with parallelly obeyed for π-π interactions. Hence, it’s favored for catalytic improvement. Secondly, rGO degradation was improved to the charge separation and may be foiling for the recombination of electron-hole pairs. Finally, transform their wide bandgap semiconductor into the catalyst to facilitate parameters. The rGO/CuCoO2 composite materials have performed well in reusability and radical abilities. The antimicrobial activity of the CuCoO2 nanoparticle was investigated on Gram-positive Staphylococcus aureus &Enterococcus faecalis and Gram-negative Escherichia coli &Pseudomonas aeruginosa bacterial strain. As promised rGO/CuCoO2 and CuCoO2 materials were examined for better degradation activities and antibacterial activities. Antibacterial efficacy studies play a major innovative role in the present work and have not been previously published. Hence, we have selected this kind of material.

Modeling and Optimization of Modified TiO2 with Aluminum and Magnesium as ETL in MAPbI3 Perovskite Solar Cells: SCAPS 1D Frameworks.

The perovskite device, incorporating a modified nanostructure of TiO2 as the electron transport layer, has been investigated to enhance its performance compared to the pure TiO2 device. Various materials undergo electrochemical doping or treatment on TiO2 to improve their photocatalytic application, thereby enhancing the current density, minimizing recombination, and improving device stability. In this study, a numerical SCAPS simulation was employed to validate experimental findings from the literature. According to the literature, this marks the first instance of doping Al3+ and Mg2+ on TiO2 due to their ionic radius comparable to that of Ti4+, at different doping concentrations. The device was modeled and simulated with the experimental parameters of bandgap, series, and shunt resistances for pure TiO2, aluminum-doped TiO2 (Al-TiO2), and magnesium-doped TiO2 (Mg-TiO2). From the validated results, the Al-TiO2 and Mg-TiO2-based devices' configurations with minimum percentage errors of 0.427 and 2.771%, respectively, were selected and simulated across nearly 90 (90) configurations to determine the optimum device model. Optimizing absorber thickness, bandgap, doping concentration, metal electrode, as well as series and shunt resistance resulted in enhanced device performance. According to the proposed model, Al-TiO2 and Mg-TiO2 configurations achieved higher power conversion efficiency values of 19.260 and 19.860%, respectively. This improvement is attributed to the reduction in recombination rates through the injection of a higher photocurrent density.

Photocatalytic applications of metal oxide-based nanocomposites for sustainable environmental remediation

Change in human lifestyle and excessive use of commercial products have caused an ecological deterioration. A major contribution towards this comes from the mixing of toxins and persistent organic pollutants into water bodies, which poses a serious risk to the ecosystem. In the above context, materials scientists are involved in the search for sustainable solutions to address the above environmental challenges by the development of advanced materials. In this study, we prepared nanocomposite materials such as; ZnO-SnO2 and ZnO-MoS2 by wet-chemical approach to degrade dye pollutants like Rhodamine B (RhB) and Congo red (CR) towards achieving environmental remediation. Powder X-ray diffraction (PXRD) measurement was done for structural characterization of the samples and the formation of the nanocomposite phase was validated by the above study. The goal of the field emission scanning electron microscopy (FESEM) study was to examine the morphology of the composites which was accompanied by the energy dispersive analysis of x-rays (EDAX) and electron mapping experiments which verified the presence of Zn, Sn, O, Mo, S elements in the respective samples. Fourier transformed infrared spectroscopy (FTIR) meas urement was conducted to investigate the vibrational properties of the samples. Photocatalytic measurement showed improved degradation efficiency of the composites as compared to the pristine samples. The degradation efficiency was found to increase with irradiation time and attained saturation after 180 min. ZnO-SnO2 nanocomposite show 91.23 % and 88.11 % of degradation for RhB and CR dyes respectively whereas 89.29 % and 83.25 % degradation have been obtained for ZnO-MoS2 for the same dyes. Several aspects of the experiment were varied, including the amount of catalyst employed, the initial dye concentration, and the pH levels, in order to assess the efficacy of the photocatalysts. Both the photocatalysts degraded CR dye most effectively at acidic pH, although RhB dye gets degraded more at neutral and alkaline pH. ZnO-SnO2 was found to be an effective photocatalyst for degrading RhB dye at neutral pH and CR dye at acidic pH. After multiple iterations of experimentation, the photocatalytic mechanism has been extensively described, and the stability and reusability of the photocatalysts have been ensured for effective environmental cleanup.

Excavating oxygen vacancies in BaZrO3 to boost photocatalysis via screening vantage crystal planes

Investigations into the design and advancement of oxygen vacancies (OVs) are at the forefront of high-efficiency catalyst research. However, the lack of experimental evidence and a comprehensive mechanistic understanding regarding the promotion of OVs poses challenges. Herein, we investigate the role of crystal planes in elucidating the mechanism of OVs formation and their impact on photocatalytic hydrogen evolution. Initially, the Vienna ab-initio simulation package was utilized to calculate the key characteristics and band parameters of BaZrO3, subsequently, the screening crystal planes of (110) was synthesized. Experimental findings indicated that the (110) crystal plane increased the OVs rate from 32 % to 56 %, consequently improving photocatalytic hydrogen evolution performance from 13.1 to 20.5 mmol·g−1·h−1. Furthermore, theoretical calculations were employed to delve into both OVs formation mechanisms and catalytic activity. This study presents an innovative approach for strategically modifying catalyst OVs for efficient and high-performance photocatalytic applications.

Exploring the Synthesis of Novel Sillenite Bi12SnO20: Effect of Calcination Temperature on the Phase Formation and Catalytic Performance

Sillenite materials have been the focus of intense research in recent years due to their unique properties and distinct structure with the I23 space group. This electronic structure has reflected high-quality applications and results for some environmental processes such as photocatalysis. This paper investigates the synthesis of a new sillenite, Bi12SnO20, and its characteristics, emphasizing its potential for photocatalytic applications. The sillenite Bi12SnO20 has been synthesized through the co-precipitation method by mixing the appropriate ratio of Bi and Sn ions. The obtained particles after precipitation and drying were characterized by thermogravimetric analysis (TGA) and then calcined at different temperatures based on this analysis. The phase has been identified by structural analysis using X-ray diffraction (XRD), and its morphology after identification was carried out by scanning electron microscopy (SEM). The calcination temperature has been found to have a critical role in obtaining the phase, where the phase was found to be formed at temperatures between 310 and 400 °C and changed to other phases within higher temperatures. The physicochemical properties of this sillenite were also studied by Fourier-transform infrared spectroscopy (FTIR) and UV Visible Spectrometer (UV-Vis). To study the obtained phases at different calcination temperatures, performance testing was performed under visible light to remove different contaminants, which are Tetracycline, Bisphenol A, and Rhodamine B. The phase Bi12SnO20 obtained at 350 °C with a catalyst dose of 1 g/L showed the highest performance for removing these pollutants with concentrations of 20 mg/L, with an efficiency of almost 100% within 2 h. This work will be useful as an important resource and strategy for the development of this sillenite material in its pure phase.

Boron nitride quantum dots supported hollow NH2-MIL-125 drive photo-Fenton-PMS system for photocatalytic tetracycline degradation: Contribution of tannic acid etching

NH2-MIL-125(Ti) materials had great potential for photocatalytic applications but had low activity due to exciton effect and narrow absorption range of visible light. The surface oxygen-containing negative functional groups of boron nitride quantum dots (BNQDs) could overcome these defects, but due to the low load capacity, a higher specific surface area of the substrate was usually required. In this paper, a hollow Ti-MOF material was developed by etching technology. The hollow structure formed by tannic acid etching broadened the absorption range of visable light and provided more alternative surfaces for loading BNQDs. The 85.2% of high tetracycline (TC) removal efficiency for the best sample (BNQDs-5@20-Ti-MOF + PMS) was obtained, which was about 56.8 and 1.9 times of the 20-Ti-MOF and BNQDs-5@20-Ti-MOF, respectively. BNQDs-5@20-Ti-MOF + PMS system showed a great TC degradation efficiency in a wide pH range (pH = 5–9). In addition, reaction temperature and the inorganic ions did not show significant inhibition effect for TC removal. Both free radical and non-free radical pathways were involved in the TC degration by BNQDs-5@20-Ti-MOF + PMS system, among which O2•− and 1O2 played the key roles. Interestingly, multiple 1O2 production paths contributed to the high efficiency and stability of BNQDs-5@20-Ti-MOF + PMS system. This study revealed a reasonable combination of Ti-MOF and BNQDs, which provided a new efficient photocatalyst for environmental remediation.

Conjugated Porous Organic Polymers Featuring Both Soft-Hard Combined Coordination Sites and Photoelectrochemical Properties for Palladium Capture and Subsequent Photocatalysis.

Palladium (Pd) capture from high-level liquid waste for subsequent photocatalytic applications is desirable for the development of nuclear energy and the reutilization of valuable resources. Herein, we approach our design with a unique porous organic polymer containing thiazolo[5,4-d]thiazole units (denoted as TzPOP-OH). It possesses two potential soft-hard (N-O and S-O) combined coordination sites for Pd(II) coordination and features strong donor-acceptor repeating units and high planarity of linkage enforced by hydrogen bonds for subsequent photocatalysis. Accordingly, TzPOP-OH with three hydroxyl groups on the linkage exhibits a high Pd(II) capacity of 369 mg g-1 at 3 M HNO3, considerably surpassing those of the controlled polymer TzPOP without hydroxyl groups and most other reported materials. Additionally, TzPOP-OH boasts other merits, including outstanding acid tolerance, extraordinary radiation stability, good reusability, and remarkable selectivity. After palladium adsorption, Pd@TzPOP-OH demonstrates impressive photodegradation efficiency to reduce the concentration of rhodamine B in contaminated urban water from 10 to less than 0.1 ppm. This work provides a feasible approach to designing materials with both suitable coordination microenvironments and semiconductor properties for metal separation and photocatalysis.

Efficient electron transport at the perovskite nanodots interface facilitates CO2 photoreduction

How to achieve controllable preparation of heterostructure and in-situ optimize the interface and internal electron transfer by a fast and economic synthesis method has become a big challenge in the practical application of photocatalysis. Herein, an island-shaped SrTiO3 (STO) perovskite nanodots and TiO2 (T) compounded S-scheme SrTiO3/TiO2 (ST) heterostructure was successfully developed. During the millisecond reaction process, the decomposed Sr2+ penetrated into the TiO2 lattice causing the lattice expansion and inducing local atomic rearrangements, resulting in the generation of STO phase. Owing to the synergy of the efficient electron transport at the perovskite nanodots interface and the stronger reduction capacity, the performance of the optimized ST1 sample is greatly improved to 86.90 μmol g−1 for CO2-to-CO and 21.31 μmol g−1 for CO2-to-CH4. The utilization of electrons reached up to 119.74 μmol g−1 h−1, which was 3.13 times higher than that of T. Detailed characterizations and density functional theory (DFT) calculations proof that the formation of intermediates HCOO− and CO32− is the key to the performance improvement critically. Overall, this work originally reports a feasible strategy for flame synthesis of S-scheme heterostructure photocatalyst.

An efficient novel NiCu@INA/rGO MOF hollow microsphere Z-scheme heterojunction catalyst for the photocatalytic degradation of tetracycline and simultaneous degradation of cationic and anionic Dyes

Bimetallic metal-organic framework materials have captivated considerable attention in photocatalysis because of their colossal properties like semiconducting, large surface area, and potent visible light harnessing ability. Self-aggregation and rapid recombination rates have greatly hindered their applications in photocatalysis. A novel reduced graphene oxide-incorporated bimetallic nickel copper metal-organic framework (NiCu@INA/rGO MOF) is fabricated using isonicotinic acid as an organic linker. A synergistic effect between the two metals increased the photocatalytic performance. Introducing reduced graphene oxide to nickel-copper MOF increased charge carrier retention transfer and enhanced the catalyst’s water dispersibility. The efficiency of the photocatalyst for the removal of tetracycline (TCn) and a mixture of Rhodamine B (RhB) and Orange G (OrG) dyes was investigated under visible light. A degradation efficiency of up to 89 % for TCn and close to ∼97.8 % and 93.5 % degradation in the case of RhB and OrG dyes was observed. The studies on the photocatalytic degradation mechanism were explored by conducting radical scavenger experiments, Electron spin resonance (ESR) studies, and Mott-Schottky analysis. TCn and RhB degradation pathways were explored by mass spectral analysis of the intermediates during the photocatalytic degradation of TCn and RhB. This work provides new paradigms for the functional modification of MOF for designing efficient photocatalysis.

Recent Research Progress on Surface Modified Graphite Carbon Nitride Nanocomposites and Their Photocatalytic Applications: An Overview

Semiconductors with visible light catalytic characteristics can realize the degradation of pollutants, CO2 reduction, and hydrogen preparation in sunlight. They have huge application value in the fields of environmental repair and green energy. Graphite phase nitride (g-C3N4, CN) is widely used in various fields such as photocatalytic degradation of pollutants due to its suitable gap width, easy preparation, low cost, fast visible light response, and rich surface activity sites. However, the absorption rate of ordinary CN on visible light is low, and the carriers are easy to recombination, making the lower optical catalytic activity. Therefore, in order to improve the photocatalytic characteristics of the CN, it is necessary to make the surface modification. This article first introduces several main methods for the current surface modification of CN, including size regulation, catalyst embedding, defect introduction, heterostructure construction, etc., and then summarizes the optical catalytic application and related mechanisms of CN. Finally, some challenges and development prospects of CN in preparation and photocatalytic applications are proposed.

Harnessing Near-Infrared Light for Highly Efficient Photocatalysis.

Near-infrared (NIR) light, accounting for approximately 50% of solar light, cannot directly excite photocatalytic reactions due to its lower energy, which severely restricts the photocatalytic solar energy conversion efficiency and hinders the application of photocatalysis. To overcome this dilemma, some viable strategies have been proposed to harness NIR light for enhancing photocatalytic performance based on material structure, composition, and function designs, and obvious progresses have been witnessed. In this review, the basic principles and representative advances in photocatalyst heterojunction designs (including p-n junctions, S-scheme, Z-scheme, and type-ІІ heterojunctions), photocatalyst composition and function designs (such as preparing rare earth element doped upconversion photocatalysts, rare earth upconversion photocatalytic hybrids and triplet-triplet annihilation upconversion photocatalytic composites), and photothermal-photocatalytic bifunction designs for NIR light utilization are exclusively scrutinized. Meanwhile, the applications of the above-mentioned NIR responsive photocatalyst composites in energy and environmental fields are summarized. Importantly, the challenges and outlooks in the field of NIR light harnessing for efficient photocatalysis are proposed, which may provide theoretical and experimental guidance to those working in solar energy conversion and utilization and other related fields.

Synthesis and photocatalytic applications of TiO2-CQDs nanocomposites prepared by biological methods

في هذه الدراسة ، تم تصنيع CQDs بالطريقة الخضراء بأستخدام عصير البرتقال والايثانول تم خلطها عند درجة حرارة منخفضة نسبيا بواسطة عملية الكربنة الحرارية المائية، وتم تحضير حبيبات TiO2 بواسطة طريقة .sol-gel وكذلك تم تحضير المركبات النانوية و TiO2-CQDs بنسب وزنية مختلفة بواسطة الخلط الانزلاقي والمعالجة الحرارية. أظهرت نتائج FESEM تكوين مواد نانوية بأشكال مختلفة وبمعدل حجم حبيبي صغير كشف المجهر الإلكتروني النافذ عالي الدقة أن TiO2 طور (anatase) يتجمع في أشكال وأحجام كروية في الغالب أقل من 15 nm. كان لنقاط الكميات الكمية قطر موحد نسبيًا، وشكل كروي ذو بنية بلورية عالية، وحجم أقل من 2 nm. تُظهر أطياف FTIR للمواد النانوية المحضرة وجود النطاق العريض عند (450–4000) cm-1 يتوافق مع اهتــزاز التمدد لمجموعات الهيدروكسيل المنتهية في العينات. أظهرت نتائج التحليل الطيفي المرئي للأشعة فوق البنفسجية أن امتصاصية المتراكبات النانوية (TiO2-CQD) تزداد مع زيادة نسبة CQDs ، وكانت قيمة فجوة الطاقة البصرية 3.14 eV و 3.07 eV للمواد TiO2 و CQDsعلى التوالي. وانخفضت قيم فجــوة الطاقة للــمتراكبات TiO2-CQDs النانــوية مع زيادة معدل CQDs ضمن المدى 1.85–2.72) eV ) . تم اختبار أداء التحفيز الضوئي عن طريق تحلل صبغات الميثيلين الأزرق (MB) والميثيل البرتقالي (MO) تحت تأثير إشعاع الأشعة الفوق البنفسجية. أظهرت النتائج أن جميع المواد المتراكبة المحضرة بنسب مختلفة كانت لها كفاءة تحفيزية ضوئية أعلى من TiO2 NPs ، وأن كفاءة التحفيز الضوئي تزداد مع زيادة نسبة . CQDs كانت كفاءة التحلل لكل من الميثيلين الأزرق (MB) والميثيل البرتقالي (MO) عند 84% و % 39 عند240 دقيقة على التوالي.

Hydrothermal growth of Zn2GeO4 nanorods for optical and (Photo)Catalytic applications: An experimental and theoretical study

From the material design perspective, we reported a systematic investigation based on theoretical and experimental approaches to explore the physical properties of Zn2GeO4 nanorods prepared by hydrothermal method with different zinc precursors for optical and (photo)catalytic applications. All ZGO samples exhibited uniform nanorod morphology with high purity and crystallinity. A negative zeta potential ranging from −13 mV to −16 mV have been observed for these nanorods. Bandgap values indicated variations among samples synthesized with different precursors. The photoluminescence and photocatalytic activities for these nanorods, have been attributed to the presence of oxygen vacancies on the Zn2GeO4 surfaces. Experimental evidence suggests that these surface defects favor the formation of hydroxyl radicals identified as primary reactive oxygen species responsible for the methylene blue photodegradation. Toxicity testing of photocatalytic residues showed minimal phytotoxic effect on lettuce seed (Lactuca sativa) germination. Additionally, Zn2GeO4 was utilized as an acid catalyst for synthesizing isoxazol-5(4H)-ones, resulting in an increase in the yield from 69 % to 92 % by using this catalyst in multicomponent reactions. Lastly, the theoretical efforts outlined in the study aim to enhance the comprehension of the material design with well-defined morphology using realist theoretical models for the Zn2GeO4 nanorods for the first time.

Phytochemically modified copper oxide-doped yttrium oxide nanoparticles for antibacterial, photocatalytic and ultralow limit biomarker detection applications

Phytochemically modified copper oxide-doped yttrium oxide nanoparticles for antibacterial, photocatalytic and ultralow limit biomarker detection applications