Photocatalytic Characteristics Research Articles

First-principles calculations to investigate structural, electronics, mechanical, and optical properties of KGaO3 cubic perovskite for photocatalytic water-splitting application

A first-principles investigation has been used to construct the crystal structure with space group 221 that has cubic nature developed in CASTEP software. A pseudo-potential plane-wave technique inside the GGA (generalized-gradient-approximation) and PBE (Perdew-Burke-Ernzerhof) exchange-correlation functional are used to investigate the KGaO3 compound. The present research report is on the structural, electronics, mechanical, and optical properties of KGaO3. The electronic properties reveal that the material is semi-conductor and has indirect band gap of 2.74 eV which reduce the electron-holes recombination. The elastic constant values were also investigated and utilized to investigate mechanical parameters such as shear modulus, Young's modulus, and Poisson's ratio. According to elastic constants calculations, KGaO3 are mechanically stable and ductile in nature. Further, refractive index, optical conductivity, the dielectric-constant, reflectivity, absorption coefficient, extinction coefficient, and loss function are calculated. According to the results, KGaO3 exhibits a high absorption in the visible region. This limits its application in photocatalytic water splitting characteristics.

Visible-light photooxidation of ciprofloxacin antibiotic contaminant over cobalt ferrite-modified BaSnO3 heterojunction

Oxidative degradation of pharmaceutical residues in different water resources by visible light photoactive nanocatalysts gains vital attention due to the severe deficiency of clear water. However, the design of an economically efficient photocatalyst remains in the research stage because of various challenges, including wide bandgap energy and fast charge recombination. This study outlines an easy hydrothermal process for creating BaSnO3 nanocrystals modified with varying amounts (4–16% wt) of CoFe2O4. Characterization revealed that the CoFe2O4 addition significantly affected the structural, optical, and photocatalytic characteristics of the prepared materials. The 12.0 wt% CoFe2O4 doping confirms the lowering in the bandgap (Eg) of BaSnO3 from 3.01 to 2.63 eV and an amelioration in the assimilation of visible light. Furthermore, the photocatalysts’ capacity to oxidize ciprofloxacin (CIP) molecules was assessed under visible light. After 90 min of irradiation, the full photooxidation of CIP over the 12 wt% CoFe2O4/BaSnO3 nanocomposite was accomplished at a larger kinetic rate constant (0.0324 min−1) than pure BaSnO3. The CoFe2O4/BaSnO3 heterojunctions displayed great stability and excellent photocatalytic applicability after being utilized five times to oxidize CIP under visible light. Photoluminescence and photocurrent density results confirmed the photocatalytic abilities and mechanism over CoFe2O4/BaSnO3 nanocomposites. Finally, this study illustrates the capability of using the mesoporous CoFe2O4/BaSnO3 nanocomposites in water remediation applications.

Synthesis of CuO@TiO2 nanocomposite and its photocatalytic and electrochemical properties. Application for treatment of azo dyes in industrial wastewater

In the present study, the photocatalytic characteristics of CuO@TiO2 nanocomposite for the decolorization of Acid Yellow 36 (AY36) are investigated. FE-SEM, XRD, EDS, and XPS structural studies of nanostructured photocatalysts showed that the CuO and TiO2 in the CuO@TiO2 (3:5) nanocomposite were successfully incorporated and formed the heterostructure. Results of optical investigations showed the optical gap energies of pure CuO, TiO2, CuO@TiO2 (1:5), CuO@TiO2 (3:5), CuO@TiO2 (5:5), and CuO@TiO2 (6:5) nanocomposite were 1.88, 3.05, 2.94, 2.81, 2.77, and 2.71 eV, respectively. According to the findings, the CuO@TiO2 nanocomposite is a potential candidate for visible light-consumed photocatalyst. Electrochemical analyses exhibited that charge transfer resistance was significantly reduced in CuO@TiO2 nanocomposite samples, indicating an effective separation of photo-excited electron-hole pairs. Photocatalytic studies reflected the fast photocatalytic degradation rate in the presence of CuO@TiO2 nanocomposites compared to pure CuO and TiO2. The results showed that 20, 30, 50, 100, and 200 mg/L of AY36 were completely eliminated after 35, 45, 65, 110, and 185 min of exposure to simulated sunlight, respectively. A CuO@TiO2 nanocomposite was effectively used to photocatalytically decolorize AY36 from actual textile wastewater after the photocatalytic performance of the material was investigated for AY36 decolorization from deionized water and industrial wastewater.

Direct synthesis of hydrogen fluoride-free multilayered Ti3C2/TiO2 composite and its applications in photocatalysis

Ti3C2/TiO2 hybrids are environment-friendly and exhibit excellent photocatalytic and hydrogen-generating power characteristics. Herein, a novel single-step method is proposed for fabricating multilayer structures in which TiO2, generated from (NH4)2TiF6, wraps the Ti3C2 MXene by etching Ti3AlC2 with (NH4)2TiF6. The optimal reaction conditions for the etching of Ti3AlC2 with (NH4)2TiF6 were systematically studied. The phase composition, morphology, and photophysical properties of the Ti3C2/TiO2 hybrids were investigated using X-ray diffraction, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, and UV–vis spectrophotometry. The thermal stability of the hybrids was investigated using thermogravimetric and differential thermal analyses. Along with the formation of Ti3C2 MXene, Ti3AlC2 reacted with (NH4)2TiF6 at 60 °C for 24 h to form hybrids surrounded by NH4TiOF3 crystals. Subsequent reactions of these hybrids with H3BO3 resulted in the conversion of NH4TiOF3 crystals into TiO2 and eventually into Ti3C2/TiO2 hybrids. Furthermore, the photocatalytic activity of the Ti3C2/TiO2 hybrids was measured by monitoring the photodegradation of methylene blue under ultraviolet light, which showed that the photocatalytic activity of the Ti3C2/TiO2 hybrids was higher than that of the commercial anatase TiO2 nanoparticles.

Contrasting photocatalytic performance of quantum-dot sensitized p-type and n-type TiO2 hierarchical nanocomposites under visible light

In recent times, titanium dioxide (TiO2) has acquired greater attention owing to its efficient photocatalytic activity, low cost, stability, non-corrosive, high availability, and nontoxicity towards the environment and humans. However, two major drawbacks including a wide band gap of around ∼3.2 eV and a high recombination rate of the photogenerated charge carriers restrict its capability in practical application. In this work, we deposited metal chalcogenide-based quantum-dots of lead sulfide (PbS QDs) on P25-, p-type and n-type TiO2 nanoparticles by pseudo-successive ionic layer adsorption and reaction (p-SILAR) process to form hierarchical nanocomposite and studied the corresponding photocatalytic activity under visible light. Concurrently, improved optoelectronic characteristics were recorded for n-TiO2/PbS hierarchical nanocomposite due to low charge recombination evidenced from photoluminescence (PL) spectra and optimum PbS deposition evidenced from EDX analysis as compared to p-TiO2 and P25–TiO2. The n-TiO2/PbS hierarchical nanocomposite degrades 74.4% RhB dye under visible light in 120 min. The structural, morphological, and photocatalytic characteristics were investigated by scanning and transmission electron microscopy, PL spectra, UV–Vis spectrophotometry, and Fourier transforms infrared spectra. This work might offer new understandings on P25-, p- and n-TiO2/PbS hierarchical nanocomposites with improved photocatalytic performance for visible-light activated degradation of RhB.

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.

Facile synthesis of graphene anchored rare earth doped mixed metal ferrite nanorods: A potential candidate for azo dye mineralization

Bandgap tuning using rare earth metals as dopants in ferrite-based photocatalytic materials has received a lot of interest because the Fermi 4f energy of these metals generates a sub-energy state in the bandgap generated by the overlapping of Fe-3d and O-2p orbitals. Herein, dysprosium-doped cobalt-nickel mixed ferrite (D-CNFO) and its graphene-reinforced composite (D-CNFO@G) were prepared and an ideal photocatalyst material for azo dye mineralization was proposed. A cost-effective combination of wet-chemical and ultrasonication methods was used to prepare the doped and composite samples. Advanced characterization methodologies were used to scrutinize the optical, compositional, structural, morphological, and photocatalytic characteristics of as-prepared materials. The X-ray diffraction analysis identified the spinel phase's (cubic) structure, while the electronic spectroscopy examination confirmed the prepared samples' rod-like morphology. The UV/visible absorbance spectrum shows the higher light harvesting behavior of the D-CNFO@G in the visible region. The mineralization performance of the D-CNFO and D-CNFO@G composites was analyzed using Congo-red (an anionic dye), a well-known azo dye. The D-CNFO@G sample removes Congo-red dye at a rate almost 2.4% faster than the D-CNFO sample. The experiment involving trapping free radicals indicates that hydroxyl radical plays a crucial role in dye degradation. Since the D-CNFO@G catalyst is magnetic and can be isolated easily from the photocatalytic system, it shows an awkward cycle activity of more than 96% after five mineralization tests. The as-prepared D-CNFO@G composite is proved as an excellent option for azo dye mineralization because of the combined impacts of rare earth doping, graphene reinforcement and nanotechnology.

Hydrothermally Synthesized Cu<sub>2</sub>ZnSnS<sub>4</sub> Nanoparticles for Photocatalytic Degradation of Rhodamine B Dye

Industrial dyes contained a wide range of organic compounds that could affect the environment and high dimensional challenges to humans. In recent years, the environmentally safe and inexpensive quaternary copper-based chalcogenide Cu2ZnSnS4 (CZTS) has emerged as a material for photovoltaics and photocatalysis. CZTS nanoparticles were prepared in this investigation using the hydrothermal route at 210 °C for 24 h without the addition of a surfactant or capping agents. Rhodamine B (RhB), a carcinogenic dye, was degraded using the synthesized material through a photocatalytic process. The structural, morphological, optical, and photocatalytic characteristics of CZTS nanoparticles were examined using X-ray diffraction (XRD), Raman spectroscopy, Field emission scanning electron microscopy (FE-SEM), and UV-vis spectroscopy. The average particle size of CZTS is found to be 31 nm with crystalline nature have been characterized by XRD. The results demonstrate that the synthesized sample has mixed morphological structures such as clew-like and flower-like structures and a bandgap of 1.50 eV. CZTS nanoparticles were used as photocatalysts under direct sunlight for Rhodamine B degradation, with the fastest degradation efficiency of 72% at 50 minutes. The results show that surfactant-free hydrothermally synthesized CZTS nanoparticles are a very promising material for the degradation of RhB dye due to the rapid degradation rate and high degradation efficiency.

Processing of Nb doped hematite for visible light photocatalytic reduction of noxious methylene blue

In this work, pristine Fe2O3 (FO, hematite) and Nb-doped Fe2O3 nanostructures with varying doping concentrations of 5%, 10%, and 15% are synthesized with hydrothermal technique. The purpose of this study is to determine the impact of doping concentration on photocatalytic activity toward mineralization of methylene blue (MB). Multiple instruments were utilized to examine the structures and functionalities of the pristine Fe2O3 (FO, hematite) and Nb-doped Fe2O3 nanostructure. The utilization of physiochemical techniques has confirmed the incorporation of Nb3+ ions into hematite. The Scherrer formula was employed to investigate the size of crystal of synthetically manufactured nanomaterials. The average particle size of undoped samples was determined to be 58 nm, while in doped samples the average nanostructure size was found to be 37 nm. The utilization of scanning electron microscopy (SEM) shows that Nb ions were able to enhance surface area and reduced particle aggregation. The band gap of FO, 5%-NFO, 10%-NFO, and 15%-NFO synthesized materials are 2.3, 2.2, 2.07 and 1.93 eV measured with UV Vis study. The exceptional photocatalytic characteristics of doped FO is attributed to a decrease in band gap energy. After 100 min, the highest level of methylene blue (MB) degradation was attained by 10%-NFO. The optimized concentration of 10%-NFO, a photocatalyst possessing a high electron trapping capacity, enhance the photoreduction process of organic dye.

Preparation and Study of Photocatalytic Properties of (M(M=Pt, Ag and Au)-TiO2)@MoS2 Nanocomposites

There have been many articles on the degradation of pollutants by binary and ternary nanocomposites in the field of photocatalysis. However, there has been no research comparing the photocatalytic performance of Rhodamine B (Rh B) between (M(M=Pt, Ag and Au)-TiO2)@MoS2 nanocomposites and binary nanocomposites. To this end, we prepared and studied (M(M=Pt, Ag and Au)-TiO2)@MoS2 nanocomposites and compared their photocatalytic degradation efficiency with binary composites and parent materials for Rhodamine B. We concluded that the best ternary polymer nanocomposite for degrading Rhodamine B is (Pt(5 wt%)-TiO2(15 wt%))@MoS2. In this work, a series of MoS2, TiO2@MoS2, and (M(M=Pt, Ag and Au)-TiO2)@MoS2 nanocomposites with various compositions were synthesized by the hydrothermal and deposition–precipitation methods, and their photocatalytic characteristics were studied in depth using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) photoluminescence spectra (PL), FTIR spectra, UV–Vis DRS spectra, and BET analyzer. The results confirmed that TiO2 and M(Pt, Ag and Au) nanoparticles (NPs) were evenly distributed on MoS2 nanosheets (NSs) to form (M(M=Pt, Ag and Au)-TiO2)@MoS2 nanocomposite heterojunction. The UV–Vis absorption spectrum test results indicated that (Pt(5 wt%)-TiO2(15 wt%))@MoS2 ternary heterojunction nanocomposites exhibited the highest photocatalysis activity, with the maximum value of 99.0% compared to 93% for TiO2(15 wt%)@MoS2, 96.5% for (Ag(5 wt%)-TiO2(15 wt%))@MoS2, and 97.8% for (Au(5 wt%)-TiO2(15 wt%))@MoS2 within 9 min. The advanced structure of (Pt-TiO2)@MoS2 improved both light harvesting and electron transfer in the photocatalytic composites, contributing to remarkable catalytic effectiveness and extended durability for the photodegradation of Rhodamine B (Rh B). In-depth discussions of the potential growth and photocatalytic mechanism, which will help improve the energy and environmental fields, are included.

Studying the Photocatalytic Characteristics of Pd Nanoparticles Created by Second Harmonic Laser Ablation

Studying the Photocatalytic Characteristics of Pd Nanoparticles Created by Second Harmonic Laser Ablation

A multifunctional non‐fluorinated flame retardant superhydrophobic 3‐D porous material for highly selective oil spill treatment and removal of dyes

AbstractThe environment and global healthcare are at risk from oily wastewater accumulation and spills. Hence, porous sponge materials are widely sought for remedial oil cleanups. Materials with superhydrophobic and photocatalytic characteristics are implemented for extensive use besides oil–water separation, self‐cleaning, and removal of dyes. Regardless of the various upsides, few materials display both of these features jointly. Most nanomaterial photocatalysts are susceptible to the action of ultraviolet (UV) light irradiation, which often inhibits their hydrophobicity. Here in this work, a photocatalyst such as ZnO was coated on a porous 3‐D melamine sponge (MS). To preserve the hydrophobicity without sacrificing the photocatalytic behavior, ZnO coated melamine sponge was modified with transparent polydimethylsiloxane (PDMS) to obtain MS/ZnO/PDMS. The obtained superhydrophobic photocatalytic sponge exhibits exceptional oil adsorption capacity, superior stability even under severe conditions and the ability to remove organic dyes. Remarkably, the sponge exhibits outstanding compressive strength and fire resistance properties, indicating the possible utilization in a prolonged practical execution. As a result, this technique might pave the way for the creation of a comprehensive design for an improved superhydrophobic photocatalytic sponge with high stability and recyclability.

A novel tertiary magnetic ZnFe2O4/BiOBr/rGO nanocomposite catalyst for photodegrading organic contaminants by visible light

A novel tertiary magnetic ZnFe2O4/BiOBr/rGO visible light-driven photocatalytic system was successfully synthesized from graphite, bismuth nitrate pentahydrate, iron (III) nitrate, and zinc nitrate precursors. The produced materials were characterized regarding micro-structure, chemical composition and functional groups, surface charge properties, photocatalytic characteristics such as band gap energy (Eg), recombination rate of charge carriers, and magnetic properties. ZnFe2O4/BiOBr/rGO heterojunction photocatalyst exhibited a saturation magnetization of 7.5 emu/g, and a visible light response (Eg = 2.08 eV). Thus, under visible light, these materials could generate effective charge carriers responsible for forming free hydroxyl radicals (HO•) for degrading organic pollutants. ZnFe2O4/BiOBr/rGO also exhibited the lowest charge carriers recombination rate compared to all individual components. The construction of ZnFe2O4/BiOBr/rGO system resulted in 1.35 to 2.55 times higher in photocatalytic degradation of DB 71 compared to individual components. At the optimal conditions (0.5 g/L catalyst load and pH 7.0), the ZnFe2O4/BiOBr/rGO system could completely degrade 30 mg/L DB 71 after 100 min. DB 71 degradation process was best described by the pseudo-first-order model, with the coefficient of determination within the range of 0.9043–0.9946 for all conditions. HO• radicals were mainly responsible for degrading the pollutant. The photocatalytic system could be effortlessly regenerated, very stable, which showed an efficiency of >80.0 % after 5 repetitive runs regarding the DB 71 photodegradation. The photocatalyst was easily recovered by a magnet. This research provides a novel approach for producing an effective and practical photocatalyst that can be applied in real organic pollutants-containing waste water treatment systems.

Comparative investigation on physicochemical and photocatalytic properties of CuS and Al3+ doped CuS thin films

By using the chemical bath approach, CuS, and Al-doped CuS thin films were formed onto glass substrates. To enhance the photocatalytic capabilities of the traditional CdS thin film, Al3+ ions were used as doping element. Investigations were done into how the amount of Al doping affected the physical characteristics of CuS films by varying Al content as 2 wt%, 4 wt%, 6 wt%, and 8 wt%). The bandgap energy, thickness, morphology, and crystalline structure of CuS and Al-doped CuS thin films were examined. By using FTIR and FT-Raman studies, the functional groups contained in the CuS and Al-doped CuS thin films were observed. EDS was used to estimate the elemental components that are present in the prepared thin films. Degradation of the textile dyes rhodamine B (RhB) and methylene blue (MB) was used to examine the photocatalytic characteristics of the produced films. Among the produced films 8 wt% Al-doped CuS thin film showed high efficiency in degradation of both MB (98 %) and RhB (98 %) dyes.

Improved photocatalytic, antimicrobial and photoelectrochemical properties of nanocrystalline Cu2+-doped ZnO nanoparticles

Herein we present the first report on the synthesis of Cu2+-doped ZnO nanoparticles via the solution-combustion using a new fuel (Glutamine). Systematic studies were carried out to assess the influence of Cu2+-concentration on photocatalytic, antimicrobial, and photoelectrochemical characteristics through various characterizations such as XRD, SEM-EDS, FTIR, UV–Visible, photocatalytic, antimicrobial, photoelectrochemical and Photoluminescence. XRD results show the formation of single-phase nanocrystalline particles and the substitution of Cu2+ at the Zn2+ site without the occurrence of impurity phases. SEM & EDS analysis revealed almost spherical particles and nominal (measured and experimental) element compositions. The structural changes induced due to the substitution of Cu2+ into the ZnO host lattice are evident in FTIR data, which show the presence of stretched ZnO bonds. The band gap narrowing effect was observed up to 5 mol% Cu2+ and thereafter band gap widens. PL spectra exhibit multiple emission peaks related to defects present in the host ZnO induced by the Cu2+ & PL intensity increases with the increase of doping concentration up to 3 mol % of Cu2+ beyond that its decreases with increasing concentration. The prepared NPs demonstrate promising photocatalytic activity against MB dye in both the UV and visible ranges. The maximum 94% percentage degradation was recorded for 9 mol% CuZnO, which is the highest among CuZnO NPs reported to date. In addition, 3 mol% and 2 mol% CuZnO NPs have shown potential antimicrobial activity against Bacillus and Pseudomonas respectively. The possible mechanism for both photocatalytic activity and antimicrobial activity is demonstrated. Furthermore, 5 mol% CuZnO has shown the largest transient photocurrent of 1.147 mA/cm2, which is ∼12 times larger than undoped ZnO (0.096 mA/cm2) due to the band-gap narrowing, suggests the possibility of photoelectrochemical sensors.

Deciphering the role of pristine and Ni ions substituted Co3O4 nanoparticles with altered structural, magnetic and dielectric traits towards elevated photosensing and photocatalytic activity

ABSTRACT Pure and nickel (Ni) doped cobalt oxide nanoparticles were employed by the co-precipitation method to present the structural, optical, and photocatalytic characteristics of NixCo3-xO4 nanoparticles (x = 0, 0.05, 0.1, and 0.3) for organic pollutant photodegradation. X-ray diffraction (XRD) was employed on NixCo3-xO4 samples with particle sizes ranging from 14 to 22 nm, confirming the occurrence of cubic phase. In addition, particle size was calculated by Debye Scherrer, Williamson-Hall (W-H) and Halder methods, respectively. The Fourier transform infrared (FTIR) analyses of all samples characterised the inherent lattice vibrations of spinel structures octahedral and tetrahedral sites, respectively. FESEM image depicts irregular-shaped clusters and EDX confirmed the presence of Ni, Co and O elements. The mesoporous nature of the pores and high BET specific surface area indicated the presence of several active sites, proving their viability as photocatalysts. UV-Vis spectrophotometer was utilised to measure the optical properties, which included recording absorption spectra and computing optical parameters. The photocatalytic activities of the pure Co3O4 and NixCo3-xO4 photocatalysts were studied by the degradation of a series of four dyes (Congo Red, Tartrazine, Rhodamine B, and Methylene Blue) solution under visible light irradiation. Compared to pure cobalt oxide, Ni-incorporated Co3O4 exhibits a substantially higher photocatalytic efficiency that increases with Ni doping concentration. The photocatalysts displayed superior recycling stability, retaining high performance after three cycles. The photosensing properties were investigated under UV light, and a considerable photocurrent enhancement was observed. As a result, it is illustrated that Ni-doped cobalt oxide NPs are a potential material for the fabrication of photosensitive devices.

Influence of calcination temperature on the microstructure and photocatalysis performance of B/Sm-TiO2 nanomaterials

In this work, we fabricated boron/samarium co-doped TiO2 nanomaterials (B/Sm-TiO2) by a sol-gel method. The effects of calcination temperature on the crystal texture, grain size, and photocatalytic characteristics were investigated by XRD, XPS, SEM, TEM, and UV–vis DRS. Using the Materials Studio software and density functional theory, the band structures and state densities of TiO2 single or codoped B and Sm ions have been determined. The photocatalytic degradation of methyl orange under visible light was used to evaluate the photocatalytic performance of B/Sm-TiO2 nanomaterials. The results demonstrate that the photocatalytic performance of B/Sm-TiO2 nanomaterials is significantly affected by different calcination temperatures. With the increase of calcination temperature, the size of TiO2 particles increases, and the TiO2 phase changes from anatase to rutile with a crystalline transition temperature of 700 °C. The visible light absorption of B/Sm-TiO2 under the forging condition of 600 °C is enhanced accordingly, the degradation efficiency is improved, and the degradation rate of methyl orange reaches 89% after 60 min of light irradiation.

An updated review of indoor pollutant purification by solar photocatalytic ventilation wall: Materials, modelling and performance evaluation

Solar photocatalysis has been an efficient option to eliminate indoor volatile organic pollutants (VOCs) due to its relatively low cost. Moreover, solar ventilation wall is a common heating and ventilating technology that supplies air circulation in a room and expels polluted air under the action of wind pressure. An efficient air purification type ventilation wall that meets indoor pollutant purification, natural ventilation and thermal fully driven by the combination of solar photocatalytic purification technology and natural ventilation wall has been developed by previous research. The aim of this updated review is to explore the development of the solar photocatalytic ventilation wall (SPVW) system and critically analyze the scientific literature on photocatalysts, models, mechanism, parameter analysis and evaluation of this multifunctional system. The review also included the effects of parameters such as initial concentrations of pollutants, ultraviolet (UV) light intensity, relative humidity, channel width, channel height on the solar photocatalytic characteristics and natural ventilation performance, and a brief performance evaluation on natural ventilation, indoor heating and solar photocatalytic degradation. The governing analysis reveals that the daily stability of the SPVW system could be achieved by enhancing the activity of the photocatalyst and decreasing fluctuation of light source in the external input.

Optical Band Gap Tuning, DFT Understandings, and Photocatalysis Performance of ZnO Nanoparticle-Doped Fe Compounds

Iron-doped Zinc oxide nanoparticles were produced by the sol-gel combustion method. This study aims to see how iron doping affects the structural, optical, and photocatalytic characteristics of ZnO composites. XRD examined all samples to detect the structural properties and proved that all active materials are a single hexagonal phase. The morphology and particle size were investigated by TEM. Computational Density functional theory (DFT) calculation of the band structure, density of state, and charge distributions for ZnO were investigated in comparison with ZnO dope iron. We reported the application results of ZnO doped Fe for Methylene blue dye removal under photocatalytic degradation effect. The iron concentrations affect the active material's band gap, producing higher photocatalytic performance. The acquired results could be employed to enhance the photocatalytic properties of ZnO.

Fabrication of nitrogen doped TiO2/Fe2O3 nanostructures for photocatalytic oxidation of methanol based wastewater

An important industrial process that often occurs on the surface of a heterogeneous catalyst using thermochemical or photochemical could help in the oxidation of methanol-based wastewater to formaldehyde. Titania-based photocatalysts have drawn a lot of interest from scientists because they are a reliable and affordable catalyst material for photocatalytic oxidation processes in the presence of light energy. In this study, a straight-forward hydrothermal method for producing n-TiO2@α-Fe2O3 composite photocatalysts and hematite (α-Fe2O3) nanocubes has been done. By adjusting the ratio of n-TiO2 in the prepared composite photocatalysts, the enhancing influence of the nitrogen-doped titania on the photocatalytic characteristics of the prepared materials was investigated. The prepared materials were thoroughly characterized using common physiochemical methods, such as transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX), X-ray photoelectrons spectroscopy (XPS), physisorption (BET), and others, in order to learn more about the structure The results obtained showed that nitrogen-doped titania outperforms non-doped titania for methanol photooxidation. The addition of nitrogen-doped titania to their surfaces resulted in an even greater improvement in the photooxidation rates of the methanol coupled with hematite. The photooxidation of methanol in the aqueous solution to simulate its concentration in the wastewater has been occurred. After 3 h, the four weight percent of n-TiO2@α-Fe2O3 photocatalyst showed the highest rate of HCHO production.