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In this study, photocatalytic degradation of acetaminophen (ACE) in aqueous solutions under simulated solar light was studied using TiO2 P25 immobilized on a glass plate by heat attachment method. The major factors affecting the removal of ACE, namely the amount and layers of TiO2 P25 immobilized, flow rate (Qv) and initial ACE concentration, were analyzed. The structural features of the TiO2 P25 immobilized were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). TiO2 was successfully immobilized on the glass plate with the structure of anatase and rutile characteristic of the pattern unmodified TiO2 P25. SEM micrographs of surface coats of TiO2 P25 immobilized on glass plates revealed microfractures, which are probably due to the different thermal expansions among the different layers of TiO2 P25 induced by the subsequent thermal treatment. The adsorption in the dark of ACE on the immobilized P25 and direct photolysis of ACE were studied, being negligible in both cases. The optimal operating conditions were 5 mg L−1 of ACE, 0.28 g of TiO2 P25 immobilized and a Qv equal to 14 mL s−1. Under these optimal conditions, 100% removal of ACE was achieved after 3 h of reaction. Moreover, a pseudo-first order kinetic model represented well the experimental data. The immobilized TiO2 P25 was regenerated six times, with no noticeable loss of photoactivity, confirming the high stability achieved by the immobilization procedure, which makes this procedure promising for real applications. [ABSTRACT FROM AUTHOR]

The use of solar-driven semiconductor photocatalysis to solve energy and environmental issues is an intriguing and difficult subject. As a consequence, various types of photocatalysts have been developed subsequently to fulfill the requirements of photocatalysis.Since graphene was discovered, materials based on graphene have garnered considerable interest. The aloe-vera derived (ADG)/nickel oxide (NiO) nanocomposite is a notable example of a graphene derivative.The uniform structure of graphene fibre is altered by nickel oxide(NiO) which tunes its band gap and causes electronic arrangements within graphene that is requiste for photocatalysis. Herein, we have used a one-pot chemical approach to design aloe vera-derived graphene/nickel oxide nanocomposites (ADG/NiO), a novel photocatalyst that show high molar absorbance, suitable band gap of 2.68 eV, good photo-stability and reusability. Under solar light irradiation, the ADG/NiO nanocomposite exhibited remarkable photocatalytic activity. It effectively fixed nitrogen into ammonia with an apparent quantum efficiency(AQE) of 0.64% and efficiently photo-oxidized dyes. Specifically, it achieved a dye removal efficiency of 94.2% for methylene blue (MB) and 86.41% for Eosin-B, converting them into harmless inorganic species like CO2 and H2O within just 90 minutes. The cost-effective ADG/NiO nanocomposite shows significant potential as a photocatalyst activated by solar light for practical applications such as the selective generation of NH3 and the purification of industrial wastewater containing dyes. [ABSTRACT FROM AUTHOR]

A novel and efficient method has been developed for synthesizing the g-C3N4@CR composite using a simple mingling and heating technique. This method involves the decoration of one-dimensional carmine (CR) onto graphitic carbon nitride (g-C3N4). The light-harvesting composites produced through this process underwent characterization using various spectroscopic techniques, including UV, XRD, FT-IR, Raman, and XPS spectroscopy. To assess the photocatalytic activity of the g-C3N4@CR Composite, its degradation efficiency was investigated by examining its performance in degrading fast green and nitrophenol dyes under outdoor solar light irradiation. The mechanism of degradation for these dyes by the newly designed g-C3N4@CR composite was elucidated through degradation kinetics analysis, involving the determination of parameters such as half-life time, rate constant, and degradation efficiency. [ABSTRACT FROM AUTHOR]

The presence of pharmaceutical pollutants in the environment has become a growing concern due to their persistence and toxic nature. In response to this issue, semiconductor photocatalyst materials have emerged as promising candidates for environmental pollutant removal, particularly under solar light irradiation. In this study, we developed a novel zeolite/Fe3O4/CuS/CuWO4 heterojunction nanocomposite through a simple and facile method. The fabrication process involved a multistep approach wherein Fe3O4, CuS, and CuWO4 were incorporated onto the surface of pure zeolite nanoparticles. X‐ray diffraction, scanning electron microscope, transmission electron microscope, ultraviolet–visible diffuse reflectance spectroscopy, Fourier transform infrared, photoluminescence, and vibrating sample magnetometry were analyzed. The results demonstrated that the zeolite/Fe3O4/CuS/CuWO4 heterojunction nanocomposite exhibited a synergistic integration of excellent properties, indicative of the successful construction of a heterostructure within the nanocomposite. Furthermore, the photocatalytic efficiency of the nanocomposite was evaluated for the degradation of the pharmaceutical pollutant fluoroquinolone levofloxacin (LEVO), and it outperformed individual photocatalysts. Notably, the zeolite/Fe3O4/CuS/CuWO4 nanocomposite achieved an impressive degradation rate of approximately 82.67% of LEVO after 120 min of exposure. Importantly, the synthesized nanocomposite demonstrated excellent reusability, with a photodegradation efficiency of 60.45% after the fifth cycle of LEVO degradation, as there was no significant loss in photocatalytic activity over repeated cycles. Furthermore the highest total organic carbon removal efficiency estimated is 57.43% for heterojunction nanocomposite. These findings highlight the potential of the zeolite/Fe3O4/CuS/CuWO4 heterojunction nanocomposite as an effective, eco‐friendly photocatalyst for pharmaceutical pollutant removal from the environment. [ABSTRACT FROM AUTHOR]

In this study, La2O3 and CeO2 nanopowders were prepared using a simple and cost-effective precipitation method. Wide-angle X-ray diffraction (WAXD), UV-Visible reflectance diffuses (UV-Vis DRS), Raman spectroscopy, and specific surface area were used to characterize the photocatalysts, evidencing that the used preparation method was effective in the generation of crystalline CeO2 and La2O3. In particular, WAXD results showed that the average crystallite size of the achieved La2O3 and CeO2 samples were about 22 nm and 28 nm, respectively. The photocatalytic performances of the prepared catalysts were investigated in the degradation of levofloxacin (LEV) and the inactivation of a waterborne pathogen levofloxacin resistant (Enterococcus faecalis ATCC 29212) by using a photoreactor equipped with a solar simulator (SS). After 120 min, the CeO2 and La2O3 photocatalytic treatments allowed us to achieve between 75% and 83% of levofloxacin removal, respectively. A complete removal of 106 CFU/mL Enterococcus faecalis ATCC 29212 was achieved after 5 and 60 min of La2O3 and CeO2 photocatalytic processes, respectively. [ABSTRACT FROM AUTHOR]

Sulfur‐doped Eosin‐B (SDE‐B) photocatalysts were synthesized for the first time utilizing sublimed sulfur (S8) as a dopant in an in situ thermal copolymerization technique. Sulfur doping not only increased Eosin‐B (E‐B) absorption range for solar radiation but also improved fixation and oxygenation capabilities. The doped sulfur bridges the S‐S bond by substituting for the edge bromine of the E‐B bond. The improved photocatalytic activity of SDE‐B in the fixation and oxygenation of NAD+/NADP+ and sulfides using solar light is attributed to the photo‐induced hole of SDE‐B's high fixation and oxygenation capacity, as well as an efficient suppression of electron and hole recombination. The powerful light‐harvesting bridge system created using SDE‐B as a photocatalyst works extremely well, resulting in high NADH/NADPH regeneration (79.58/76.36%) and good sulfoxide yields (98.9%) under solar light. This study focuses on the creation and implementation of a sulfur‐doped photocatalyst for direct fine chemical regeneration and organic transformation. [ABSTRACT FROM AUTHOR]

Effective disinfection processes have been investigated to provide pathogen-free drinking water. Due to growing concern about the potential negative effects of cyanobacteria in portable water, their treatment has gained more attention recently. This study aims to compare the inhibition efficiencies of Gram-negative bacteria (Escherichia coli; E. coli), Gram-positive bacteria (Bacillus subtilis; B. subtilis), and cyanobacteria (Microcystis aeruginosa; M. aeruginosa) using UV-C and solar irradiation, and their combination process with H2O2. Over 6 log removal value (LRV) of E. coli and B. subtilis was achieved within 1 min of UV-C irradiation (0.76 ± 0.02 mW/cm2). The solar and solar/H2O2 (50 mg/L) processes effectively reduced (>99%) both bacteria after 20 min. E. coli was more sensitive to hydroxyl radicals (•OH) compared to the B. subtilis due to a different cell wall structure, resulting in a 0.18–0.62 higher LRV than B. subtilis. However, solar-based processes did not effectively inhibit M. aeruginosa (>52.23%). The UV-C/H2O2 (50 mg/L) process showed the highest inhibition rate for M. aeruginosa (77.83%) due to the generation of •OH, leading to oxidative damage to cells. Additionally, chlorophyll-a (Chl-a) was measured to indicate cell lysis of M. aeruginosa. The removal rate of Chl-a extracted by viable M. aeruginosa was higher using the UV-C process (93.03%) rather than the UV-C/H2O2 process (80.95%), because UV-C irradiation could be most effective in damaging Chl-a. [ABSTRACT FROM AUTHOR]

Glucose, an abundant and renewable form of biomass, has garnered significant attention in research for its conversion into high‐value chemicals such as gluconic acid. Traditional methods for biomass transformation typically involve high energy input, elevated temperature, pressure, and costly systems. In contrast, photocatalysis emerges as a promising approach to produce organic molecules under mild conditions, harnessing energy from natural sunlight or lamps. This study presents the nitrogen‐enriched graphene with zeolite second Mobil–5 (NenG/ZSM‐5) photocatalyst, evaluated for generating high‐value chemicals (gluconic acid and leucodopaminechrome) under solar light irradiation. The NenG/ZSM‐5 photocatalyst, synthesized from nitrogen‐doped graphene and ZSM‐5, successfully converted dopamine into leucodopaminechrome (71.54 %) — a critical step in dopamine regeneration and transformed glucose into gluconic acid (85 %). The addition of ZSM‐5 to NenG provided stability and enhanced product selectivity. The outstanding performance of the NenG/ZSM‐5 photocatalyst can be attributed to its heightened solar light harvesting potential, appropriate energy band gap, and uniformly arranged π‐electron channels. This research focuses on solar conversion of glucose to gluconic acid and dopamine regeneration, with potential for further exploration in the research domain. [ABSTRACT FROM AUTHOR]

The photoelectrochemical characterization of the spinel NiCr2O4 synthetized by sol gel route was investigated. The thermal analysis showed that the single phase is formed above 530 °C as confirmed by X-ray diffraction. The direct optical transition (1.79 eV), determined from the diffuse reflectance, is assigned to the lifting degeneracy of Cr3+: 3d3 orbital octahedrally bonded to O2− ions. Field-dependent magnetization, measured at 300 K in the range (± 20 kOe), shows a maximum magnetization of ~ 0.16 emu/g with no saturation and a weak coercivity of 67 Oe. The thermal variation of the electrical conductivity indicates localized 3d-electrons and the data are fitted by a low lattice-polaron hopping with an activation energy of 0.17 eV, characteristic of a semiconducting behavior. A flat band potential (Efb) of − 0.23 VSCE with p-type nature was deduced from the variation of the capacitance (C−2) on the potential (E) of the junction NiCr2O4/Na2SO4. The p-type conduction is corroborated by the positive thermo-power (S300K = 123 µV K−1), supporting the non-degenerate semi-conductivity. The electron transfer from the conduction band (− 1.85 VSCE) to dissolved oxygen is predicted from the potential diagram, constructed from the physic-chemical properties; this allows the oxidation of Orange II (O II) upon solar light. Similarly, ZnO enhanced the photoactivity by 68% with loading the spinel as sensitizer. O II is mineralized by O2•− radicals at pH ~ 7 within 1 h on the heterosystem NiCr2O4 (60%)/ZnO for O II concentration of 20 mg L−1. The removal color obeys a pseudo first order kinetic with a rate constant of 0.023 min−1 (t1/2 = 23 min). [ABSTRACT FROM AUTHOR]

Solar light-induced aqueous crystal violet (CV) dye degradation was carried out on α-zirconium phosphate/graphitic carbon nitride (α-ZrP/g-C3N4) nanocomposite. α-ZrP was synthesized by direct precipitation of zirconium oxychloride with phosphoric acid. g-C3N4 was prepared by thermal decomposition of melamine. α-ZrP/g-C3N4 nanocomposite was synthesized by the direct precipitation of zirconium phosphate on the surface of g-C3N4. Powder X-ray diffraction pattern confirmed the formation of pure α-ZrP, g-C3N4, and α-ZrP/g-C3N4 nanocomposites with crystallite sizes of 51.3 nm, 8.9 nm, and 46.4 nm, respectively. SEM images of α-ZrP showed plate-like morphology and g-C3N4 showed a layered structure with buckled and backfolded edges. XPS and EDX spectrum of the α-ZrP/g-C3N4 nanocomposite shows the presence of Zr, P, N, C, and O elements. The optical absorption wavelength/band gap of the α-ZrP, g-C3N4, and α-ZrP/g-C3N4 nanocomposites were 394.7 nm/3.33 eV, 494.3 nm/2.66 eV, and 457.5 nm/2.85 eV, respectively. The degradation efficiency toward CV dye was found in the order of α-ZrP < g-C3N4 < α-ZrP/g-C3N4 nanocomposite. The degradation efficiency increases with an increase in time, and the pseudo-first-order kinetics model was fitted well. The rate constant of the α-ZrP/g-C3N4 nanocomposite was found four times higher than that of g-C3N4 and ten times of the α-ZrP. The photocatalytic degradation of CV dye under solar light occurred via oxidation by hydroxyl radical and was maximum at pH 6. The photocatalytic degradation efficiency decreases in the presence of anions. α-ZrP/g-C3N4 nanocomposite is easy to synthesize, low-cost, and has high degradation efficiency, making it a promising photocatalyst to clean water containing CV dye under solar light. [ABSTRACT FROM AUTHOR]

BiVO4 is an important n-type semiconductor used in photocatalysis due to its high capacity to absorb solar light in the 400–700 nm range, abundance, high chemical stability, non-toxicity, and low cost. However, research on physicochemical modifications to increase its catalytic activity via simple procedures is limited. In this work, the influence of different synthesis parameters, such as calcination temperatures or silver doping, on the structural and physicochemical characteristic of the BiVO4-based photocatalysts and their photocatalytic performance in degrading sulfamethoxazole from aqueous solution under blue-LED irradiation was evaluated. BiVO4-based photocatalysts were synthesized using a solvothermal method. The monoclinic phase (m-s) was successfully kept stable even after the thermal treatments at 300, 450, and 600 °C and the corresponding silver doping. The low bandgap of 2.40 eV and the average particle size of 18 nm of the BiVO4 catalyst treated at 300 °C seems to be the key. Afte doping, Ag/BiVO4 photocatalyst treated at the optimal found calcination temperature (300 °C) showed the best photocatalytic behavior. [ABSTRACT FROM AUTHOR]

Photocatalysis is a promising route to convert solar light into chemical energy for H 2 evolution and pollutants degradation. Hence, Ni 2 P decorated ZnCr 2 O 4 (Ni 2 P/ZnCr 2 O 4) nanofibers were prepared for boosting solar-light induced water splitting and tetracycline hydrochloride (TCH) degradation. For comparison to ZnCr 2 O 4 nanofibers, Ni 2 P/ZnCr 2 O 4 composites exhibited the better photocatalytic activities for water splitting and TCH removal. Owing to the co-catalytic effect of Ni 2 P for the efficient photon capture, the charge carriers were rapidly separated and migrated at the interface between Ni 2 P and oxygen-defected ZnCr 2 O 4. H 2 evolution rate of optimal C–Ni 2 P/ZnCr 2 O 4 with a nominal Ni 2 P content of 9.0 wt% was 575.89 μmol g−1 h−1, and its apparent quantum yield at 420 nm was 15.25 %, while its H 2 evolution decreased from 2815.13 to 2602.51 μmol g−1 after fifth cycle. In addition, the removal efficiency of C–Ni 2 P/ZnCr 2 O 4 was 93.68 % within 90 min, and declined to 88.76 % after five cycles for solar-light driven degradation of 50 mg L−1 TCH solution. The deactivation of C–Ni 2 P/ZnCr 2 O 4 was due to the photo-corrosion for the change in valence states of compositions. [ABSTRACT FROM AUTHOR]

Yttrium orthovanadate (YVO 4), a wide-bandgap photocatalyst was tuned into a visible responsive material by anchoring an organic framework on the surface of YVO 4 nanoparticles using polyethyleneimine (PEI). The surface organic framework was identified as the decomposed PEI derivatives with the carbonyl and carboxylic acid functional groups by the FTIR and XPS analyses. The top of the valence band (VB) was raised and the bottom of the conduction band was moved down; hence, the band gap of YVO 4 was reduced to absorb the light in the visible region for all three synthesized samples, which was confirmed by DRS UV–Vis analysis. The functional groups facilitated more water molecules on the YVO 4 surface via hydrogen bonding; hence, the YVO 4 surface acquired superhydrophilicity. Among the three YI, YII, and YIII samples synthesized with three different calcination temperatures of 80, 260 and 400 °C respectively, YII showed many advantageous photocatalytic properties. The optimum loading of organic compounds obtained on YII surface at 260 °C, which improved the surface area, visible light absorption, hydrophilicity, and exciton's life. Hence, YII showed a better performance of 3.75 mmol h−1g−1 cat H 2 production than YI and YII. This work interestingly revealed the influence of calcination temperature on surface functionalization and the performance of catalytic materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Although using solar energy for pharmaceutical manufacture presents hurdles, the potential benefits in terms of sustainability, cost-effectiveness, and technical innovation make it an exciting path for the scientific community to investigate and develop further. We present a highly efficient solar light active supramolecular network organogels as a photocatalyst. The as-prepared PVA@RhB and PVA@RhB@OG organogels as a photocatalyst catalytic materials were used to create C-N and C-S bonds for drug intermediates and value-added products because of their high bond energy, low polarity, and strong inertia C-H bond activation. The current research work sets a new standard for the environmentally friendly, highly selective C-H activation for the production of C-N/C-S bonds under solar light. Highlights: Aeobic oxidative cyclization for C-N and C-S bond formation. Optimization table to revealed the photocatalytic activity of photocatalyst. Various characterization like UV, FTIR, XRD, CV, Tafel, and EIS have disscused for superiority of PVA@RhB and PVA@RhB@OG organogel photocatalyst. [ABSTRACT FROM AUTHOR]

In the pursuit of efficient photocatalytic materials for environmental applications, a new series of g-C3N4/N-doped CeO2 nanocomposites (g-C3N4/N-CeO2 NCs) was synthesized using a straightforward dispersion method. These nanocomposites were systematically characterized to understand their structural, optical, and chemical properties. The photocatalytic performance of g-C3N4/N-CeO2 NCs was evaluated by investigating their ability to degrade methylene blue (MB) dye, a model organic pollutant. The results demonstrate that the integration of g-C3N4 with N-doped CeO2 NCs reduces the optical energy gap compared to pristine N-doped CeO2, leading to enhanced photocatalytic efficiency. It is benefited from the existence of g-C3N4/N-CeO2 NCs not only in promoting the charge separation and inhibits the fast charge recombination but also in improving photocatalytic oxidation performance. Hence, this study highlights the potential of g-C3N4/N-CeO2 NCs as promising candidates for various photocatalytic applications, contributing to the advancement of sustainable environmental remediation technologies. [ABSTRACT FROM AUTHOR]

Elevated global pollution level is the prime reason that contributes to the onset of various harmful health diseases. The products of Biginelli reaction are enormously used in the pharmaceutical industry as they have antiviral, antibacterial, and calcium channel modulation abilities. This work reports a novel eosin Y sensitized boron graphitic carbon nitride (EY‐Ben‐g‐C3N4) as a photocatalyst that efficiently produced 3,4‐dihydropyrimidine‐2‐(1H)‐one by the Biginelli reaction of benzaldehyde, urea, and methyl acetoacetate. The photocatalyst EY‐Ben‐g‐C3N4 showed a successful generation of 3,4‐dihydropyrimidine‐2‐(1H)‐one (Biginelli product) in good yield via photocatalysis which is an eco‐friendly method and has facile operational process. In addition to the production of Biginelli products, the photocatalyst also showed a remarkable NADH regeneration of 81.18%. The incorporation of g‐C3N4 with boron helps increase the surface area and the incorporation of eosin Y which is an inexpensive and non‐toxic dye, and in Ben‐g‐C3N4, enhanced the light‐harvesting capacity of the photocatalyst. The production of 3,4‐dihydropyrimidine‐2‐(1H)‐one and NADH by the EY‐Ben‐g‐C3N4 photocatalyst is attributed to the requisite band gap, high molar absorbance, low rate of charge recombination, and increased capacity of the photocatalyst to harvest solar light energy. [ABSTRACT FROM AUTHOR]

The objective of this study is to create a planar solar light absorber that exhibits exceptional absorption characteristics spanning from visible light to infrared across an ultra-wide spectral range. The eight layered structures of the absorber, from top to bottom, consisted of Al2O3, Ti, Al2O3, Ti, Al2O3, Ni, Al2O3, and Al. The COMSOL Multiphysics® simulation software (version 6.0) was utilized to construct the absorber model and perform simulation analyses. The first significant finding of this study is that as compared to absorbers featuring seven-layered structures (excluding the top Al2O3 layer) or using TiO2 or SiO2 layers as substituted for Al2O3 layer, the presence of the top Al2O3 layer demonstrated superior anti-reflection properties. Another noteworthy finding was that the top Al2O3 layer provided better impedance matching compared to scenarios where it was absent or replaced with TiO2 or SiO2 layers, enhancing the absorber's overall efficiency. Consequently, across the ultra-wideband spectrum spanning 350 to 1970 nm, the average absorptivity reached an impressive 96.76%. One significant novelty of this study was the utilization of various top-layer materials to assess the absorption and reflection spectra, along with the optical-impedance-matching properties of the designed absorber. Another notable contribution was the successful implementation of evaporation techniques for depositing and manufacturing this optimized absorber. A further innovation involved the use of transmission electron microscopy to observe the thickness of each deposition layer. Subsequently, the simulated and calculated absorption spectra of solar energy across the AM1.5 spectrum for both the designed and fabricated absorbers were compared, demonstrating a match between the measured and simulated results. [ABSTRACT FROM AUTHOR]

The present work deals with removing Rhodamine B (Rh B) from aqueous solution by Photo Sono-assisted catalytic process on CoFe2O4 elaborated by sol–gel method. The spinel identified by X-ray diffraction presents a face-centered cubic lattice with a grain size of 360 (± 2 nm) and a zeta potential of − 33 mV. The oxide is characterized by diffuse reflectance and photo-electrochemistry. The direct gap (1.42 eV) is assigned to the internal transition: F e oc 3 + : t 2 g → F e oc 4 + : e g in agreement with the red color. The narrow valence band deriving from Fe3+: 3d parentage induces a low hole mobility (µh = 8.91 × 10−6 cm2 V−1 s−1). The electrical conductivity of CoFe2O4 is characteristic of semiconducting comportment with activation energy (Ea) of 0.57 eV, where the electron jump occurs by small lattice polaron between mixed valences Fe3+/Fe4+. The intensity potential J(E) profile in Na2SO4 (10–2 M) exhibits a small hysteresis loop. The chrono-amperometry shows p-type conductivity due to metal insertion, a result confirmed by the capacitance measurement where a hole density (NA) of 0.176 × 1023 cm−3 and a flat band potential (Efb) equal to − 0.8 V are determined. As an application, Rh B (20 mg L−1) is successfully oxidized by photocatalysis on CoFe2O4 with a reduction of 53% under solar light. An enhancement up to 88% has been reached by sono-photocatalysis at an ultrasonic wave (USW) frequency (60 kHz, 550 W) within 105 min.; the Rh B elimination follows a pseudo-first-order kinetic with a rate constant of 1.23 × 10–2 mn−1 (t1/2 = 56 min), and a reaction mechanism is suggested, was entirely discolored in the USW/solar light/CoFe2O4 system. The Sono-photocatalytic degradation of Rh B depends on the initial Rh B concentration, acoustic power, and catalyst dose. At low ultrasound frequency, the results indicated a total chemical oxygen demand (COD) when applying the system USW/solar light/CoFe2O4, signifying its great potentiality for the treatment of water. [ABSTRACT FROM AUTHOR]

The photo-induced peroxymonosulfate (photo-PMS) reaction is a promising route to eliminate antibiotics from waste water. To achieve excellent photo-PMS activity in Mg–Fe layered double hydroxides (LDHs) for tetracycline hydrochloride (TCH) degradation under simulative solar-light irradiation, Mg–Fe LDHs-loaded polyacrylonitrile (Mg–Fe/PAN) nanofibers were in-situ prepared via the hydrothermal route. For comparison to the photocatalysis and photo-PMS process, the Mg–Fe/PAN-assisted photo-PMS process exhibited a better elimination activity for TCH elimination. In addition, the photo-PMS activities of Mg–Fe/PAN composites were greatly affected by Mg–Fe LDHs content, TCH concentration, pH, and inorganic salts. Among these Mg–Fe/PAN composites, the optimal MgFe2/PAN with a Mg/Fe molar ratio of 1:2 and a nominal Mg–Fe LDHs content of 2.0 wt. % removed 81.31% TCH solution of 80 mg L−1 TCH within 120 min. This enhanced photo-PMS capacity of MgFe2/PAN was ascribed to the abundant active sites formed by functional groups and oxygen defects for efficient TCH species adsorption and photon capturing, and the tight interface between Mg–Fe LDHs nanoparticles and PAN nanofibers for the rapid separation and transfer of photoinduced e−/h+ pairs. SO4•− and •O2− radicals were vital for the MgFe2/PAN-assisted photo-PMS reaction. [ABSTRACT FROM AUTHOR]

The combination of excellent electronic properties and thermal stability positions orange‐derived graphene quantum dots (GQDs) as promising materials for solar light‐based applications. Researchers are actively exploring their potential in fields such as photovoltaics, photocatalysis, optoelectronics, and energy storage. Their abundance, cost‐effectiveness, and eco‐friendly nature further contribute to their growing relevance in cutting‐edge scientific research. Furthermore, only GQDs are not much more effective in the UV‐visible region, therefore, required band gap engineering in GQDs material. In this context, we designed GQDs‐based light harvesting materials, which is active in UV‐visible region. Herein we synthesized GQDs coupled with 2,6‐diaminoanthrquninone (AQ), that is, GQDs@AQ light harvesting photocatalyst the first time for the oxidation of sulfide to sulfoxide under visible light. For the integrating reactions of sulfide in aerobic conditions under visible light by GQDs@AQ photocatalyst exhibit utmost higher photocatalytic activity than simple GQDs due to low molar extinction coefficient and slow recombination charges. The use of GQDs@AQ light harvesting photocatalyst, showed the excellent organic transformation efficiency of sulfide to sulfoxide with excellent yield (94%). The high efficiency and excellent yield of 94% indicate the effectiveness of GQDs@AQ as a photocatalyst for these specific organic transformations. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) are attracting increasing interests as photocatalysts for solar-driven hydrogen production from water. This paper reports on a comparative study of using either acetic acid (AA) or trifluoroacetic acid (TFA) as the representative UiO-66 organic modulators for synthesizing visible light responsive UiO-66(Zr)-X (X: NH2 or NO2) photocatalysts for water splitting. The results show that photocatalytic hydrogen generation from a water/methanol mixture can be improved by varying the nature and amount of the modulator employed to prepare the different UiO-66(Zr)-X (X: NH2 or NO2) solid derivatives. UiO-66(Zr)-NH2 was the most active photocatalyst, followed by UiO-66(Zr)-NO2, both prepared with 12 equivalents of AA with respect to the organic ligand. This UiO-66(Zr)-NH2 solid was more active than the parent MOF in photocatalytic overall water splitting (OWS) (H2 and O2 production of 450 and 160 µmol·g−1, respectively, in 5 h; apparent quantum yield (AQY) at 400 nm of 0.06%) in the absence of methanol and compares favourably with analogous reports. Information on the photocatalytic activity of the most active solids of both series was obtained by means of a series of techniques, including ultraviolet–visible (UV–vis) diffuse reflectance, X-ray photoelectron spectroscopy (XPS), laser flash photolysis (LFP), electron spin resonance (ESR), photoluminescence and photoelectrochemical measurements together with density functional theory (DFT) calculations. The results showed that organic acid modulators can be used to enhance the photocatalytic activity of missing linker UiO-66 defective materials in solar-powered water splitting. [ABSTRACT FROM AUTHOR]

Concerns about per‐ and polyfluoroalkyl substances (PFAS) pollution are escalating globally due to the discovery of their widespread environmental distribution, accompanied by their migration, bioaccumulation, and toxic potential for plants, animals, and humans. Several technologies have been developed for their remediation since standard water treatment methods often fail. However, these approaches require large energy consumption and, at times, exacerbate environmental issues. In this context, photocatalytic degradation holds promise as a reliable technological solution for PFAS mineralization. However, to date, it primarily relies on the degradation of perfluorooctanoic acid using high‐energy gap semiconductor oxides that necessitate high‐power artificial ultraviolet sources for excitation and, at times, the use of strong chemical oxidants. This review examines chemical‐free catalysts and mechanisms recently documented in the literature to outline a roadmap for the realization of solar‐driven mineralization of all PFAS compounds. To this end, conventional wide‐bandgap semiconductor oxides are delved into and strategies to extend their spectral absorbance while enhancing charge separation with a focus on the proposed degradation pathways are explored, that are fundamental to designing technologically relevant photodegradation systems. [ABSTRACT FROM AUTHOR]

Z-scheme heterojunction Bi2WO6/g-C3N4 was obtained by a novel hydrothermal process; its photocatalysis–persulfate (PDS) activation for tetracycline (TC) removal was explored under solar light (SL). The structure and photoelectrochemistry behavior of fabricated samples were well characterized by FT-IR, XRD, XPS, SEM-EDS, UV-vis DRS, Mott-Schottky, PL, photocurrent response, EIS and BET. The critical experimental factors in TC decomposition were investigated, including the Bi2WO6 doping ratio, catalyst dosage, TC concentration, PDS dose, pH, co-existing ion and humic acid (HA). The optimum test conditions were as follows: 0.4 g/L Bi2WO6/g-C3N4 (BC-3), 20 mg/L TC, 20 mg/L PDS and pH = 6.49, and the maximum removal efficiency of TC was 98.0% in 60 min. The decomposition rate in BC-3/SL/PDS system (0.0446 min−1) was 3.05 times higher than that of the g-C3N4/SL/PDS system (0.0146 min−1), which might be caused by the high-efficiency electron transfer inside the Z-scheme Bi2WO6/g-C3N4 heterojunction. Furthermore, the photogenerated hole (h+), superoxide (O2•−), sulfate radical (SO4•−) and singlet oxygen (1O2) were confirmed as the key oxidation factors in the BC-3/SL/PDS system for TC degradation by a free radical quenching experiment. Particularly, BC-3 possessed a wide application potential in actual antibiotic wastewater treatment for its superior catalytic performance that emerged in the experiment of co-existing components. [ABSTRACT FROM AUTHOR]

Fluorinated and enzymatic chemicals are widely used in society due to their chemical, physical, and biological qualities. Nevertheless, despite their vital importance, present approaches to adding fluorine to molecules and regenerating enzyme cofactors have serious flaws. For instance, numerous approaches are photocatalytic and employ stoichiometric counterparts of heavy metals. Prevailing photocatalytic approaches, on the other hand, show very poor activity, and selectivity has not been attained by heterogeneous photocatalysis, despite the several benefits such a method would provide. Here, we show how heterogeneous photocatalysis may be used to selectively create C(sp3)‐F bonds and 1,4‐NADH regeneration cofactor. Employing NiS‐NiO/S‐g‐C3N4 nanocomposite photocatalyst as a photocatalyst, NAD+ and Selectfluor as an acceptor and mild fluorine donor, effective 1,4‐NADH regeneration, and decarboxylative fluorination of carboxylic acids can be attained in very short reaction times. Furthermore, NiS‐NiO/S‐g‐C3N4 nanocomposite photocatalyst exhibits outstanding levels of robustness and photo‐catching capacity. These aspects, attached to the mild environment of the reaction scheme, exhibit a breakthrough toward the sustainable cofactor of 1,4‐NADH regeneration and synthesis of fluorinated compounds. [ABSTRACT FROM AUTHOR]

The increasing demand for efficient wastewater treatment technologies, driven by global population growth and industrialisation, highlights the necessity for advanced, reliable solutions. This study investigated the efficacy of a slurry photocatalytic membrane reactor (PMR) for the advanced removal of organic pollutants, quantified via chemical oxygen demand (COD), under natural and simulated solar light irradiation. Employing two variants of iron-doped titania as photocatalysts and a polysulfone-based polymeric membrane for the separation process, the investigation showcased COD removal efficiencies ranging from 66–85% under simulated solar light to 52–81% under natural sunlight over a 7 h irradiation period. The overall PMR system demonstrated COD removal efficiencies of 84–95%. The results confirmed the enhanced photocatalytic activity afforded by iron doping and establish solar-powered slurry PMRs as an effective, low-energy, and environmentally friendly alternative for the advanced treatment of municipal wastewater, with the research providing valuable insights into sustainable water management practices. [ABSTRACT FROM AUTHOR]

Graphene-based nanocomposites are developing as a new class of materials with several uses. The varied weight percentages of rGO on Ag2S catalysts were synthesized using a simple hydrothermal process and employed for the decomposition of anionic dye naphthol green B (NGB) under solar light. The reduced graphene oxide-based silver sulfide (rGO/Ag2S) nanoparticles were then examined using XRD, SEM, EDS, HR-TEM, XPS, UV-DRS, and PL analysis. Using solar light, the photocatalytic activity of the produced catalyst was examined for the degradation of naphthol green B (NGB) in an aqueous solution. At pH 9, rGO/Ag2S is discovered to be more effective than the other catalysts for the NGB dye mineralization. Analyses have been conducted on the influence of operational parameters on the photo-mineralization of NGB, including the initial pH, initial dye concentration, and catalyst dosage. The dye concentration increased; the efficiency of photocatalytic degradation tended to decrease. Chemical oxygen demand (COD) studies have verified the NGB dye mineralization. Active species trapping revealed that holes, hydroxyl radicals, and superoxide radicals all played major roles in the photocatalytic deterioration of NGB processes. Additionally, a potential mechanism of NGB dye degradation by rGO/Ag2S catalyst is presented. The synthesized compound was further evaluated for antibacterial activity, and the results indicated that rGO/Ag2S were potentially effective antibacterial agents. [ABSTRACT FROM AUTHOR]

In this study, La2O3 and CeO2 nanopowders were prepared using a simple and cost-effective precipitation method. Wide-angle X-ray diffraction (WAXD), UV-Visible reflectance diffuses (UV-Vis DRS), Raman spectroscopy, and specific surface area were used to characterize the photocatalysts, evidencing that the used preparation method was effective in the generation of crystalline CeO2 and La2O3. In particular, WAXD results showed that the average crystallite size of the achieved La2O3 and CeO2 samples were about 22 nm and 28 nm, respectively. The photocatalytic performances of the prepared catalysts were investigated in the degradation of levofloxacin (LEV) and the inactivation of a waterborne pathogen levofloxacin resistant (Enterococcus faecalis ATCC 29212) by using a photoreactor equipped with a solar simulator (SS). After 120 min, the CeO2 and La2O3 photocatalytic treatments allowed us to achieve between 75% and 83% of levofloxacin removal, respectively. A complete removal of 106 CFU/mL Enterococcus faecalis ATCC 29212 was achieved after 5 and 60 min of La2O3 and CeO2 photocatalytic processes, respectively.

In this study, using a co-precipitation method, MnFe 2 O 4 spinel ferrite nanoparticles (NPs) doped with chromium and copper have been synthesized. Additionally, we have prepared nanocomposites (NCs) by incorporating 10 % reduced graphene oxide (r-GO) through ultra-sonication. This research investigates the influence of Cr and Cu doping and the addition of r-GO on different physicochemical properties, including structural characteristics, electrical behavior, and photocatalytic performance. Fabricated materials were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and Raman scattering. According to the structural study, Cr & Cu doped and rGO-reinforced MnFe 2 O 4 spinel ferrite was formed successfully. The electrical conductivity of the ferrite nanocatalyst increased with Cr and Cu doping and r-GO addition. The BET surface area measurements for the bare, co-doped, and composite materials yielded 68 m2g-1, 94 m2g-1, and 139 m2g-1, respectively. The MnFe 2 O 4 /r-GO nanocomposite showed a notable aptitude for photo-degradation of RhB dye, achieving a degradation rate of around 98.48 % during 50-min duration under sunlight irradiation. The bare and co-doped equivalents exhibited deterioration rates of 39.86 % and 61.27 %, respectively. The photocatalyst is stable, losing just 1.27 % of its activity after five reusability tests. Scavenging radical results show that the hydroxyl (OH•) and e−/h + species are mainly involved in the degradation of RhB dye. MnFe 2 O 4 /r-GO NCs' highly porous texture, low band gap, larger surface area, and well-conducting nanosheets enhance dye degradation, making the composite material a promising environmental remediation material. [Display omitted] [ABSTRACT FROM AUTHOR]

In the pursuit of advancing novel photocatalytic solutions for removal methylene blue (MB) from aqueous environments, our investigation centered on harnessing the potential of red alga valorization. By employing meticulous characterization techniques, we observed a transformative conversion of powdered alga into calcium oxide, distinguished by intricately structured and uniformly porous qualities. Furthermore, the analysis of UV outcomes unveiled a remarkably narrow band gap energy (2.61 eV) within the photocatalyst. Notably, our catalytic system exhibited exceptional prowess in the solar-driven photodegradation of methylene blue, achieving a substantial degradation efficiency (96%) within a brief 20-min interval. Conclusively, this study has unveiled the latent potential of red alga as an auspicious foundation for pioneering the evolution of novel photocatalytic agents. [ABSTRACT FROM AUTHOR]

With the backdrop of "Carbon peaking and carbon neutrality goals", the development of renewable energy and solar energy storage has gained countless attention recently. However, the lack of experiments involving energy conversion in undergraduate curricula has limited students' understanding of low-carbon and green chemistry to remain largely theoretical. This experimental protocol aims to synthesize hydrogen peroxide (H2O2), utilizing the solarto-chemical conversion, all while aligning with cutting-edge scientific advancements. The entire experimental process refrains from the use of any toxic or hazardous reagents, truly embodying the principles of green and low-carbon chemistry. Illustrating with the synthesis of graphitic carbon nitride (g-C3N4) nanosheets via dicyandiamide, this experiment delves into the mechanism of polymerization reaction. This approach integrates fundamental operations from inorganic, physical, and analytical chemistry, coupled with modern analytical methods, to conduct open-ended comprehensive experiments on the g-C3N4 catalyzed generation of H2O2 and quantification. By combining the polymerization reaction of inorganic and organic materials within an aerobic experimental environment and employing UV spectrophotometry for yield measurement, this experiment effectively enhances students' comprehensive qualities and innovative abilities, achieving the goal of "integrating current affairs into teaching and cultivating well-rounded students". [ABSTRACT FROM AUTHOR]

This study presents a relatively low-cost method for modifying TiO2-based materials for photocatalytic bacterial inactivation. The photocatalytic inactivation of Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus epidermidis) bacteria using modified sulphated TiO2 was studied. The modification focused on the reduction of TiO2 by ammonia agents and hydrogen at 400–450 °C. The results showed a high impact of sulphate species on the inactivation of E. coli. The presence of these species generated acid sites on TiO2, which shifted the pH of the reacted titania slurry solution to lower values, around 4.6. At such a low pH, TiO2 was positively charged. The ammonia solution caused the removal of sulphate species from TiO2. On the other hand, hydrogen and ammonia molecules accelerated the removal of sulphur species from TiO2, as did heating it to 450 °C. Total inactivation of E. coli was obtained within 30 min of simulated solar light irradiation on TiO2 heat-treated at 400 °C in an atmosphere of Ar or NH3. The S. epidermidis strain was more resistant to photocatalytic oxidation. The contact of these bacteria with the active titania surface is important, but a higher oxidation force is necessary to destroy their cell membrane walls because of their thicker cell wall than E. coli. Therefore, the ability of a photocatalyst to produce ROS (reactive oxidative species) will determine its ability to inactivate S. epidermidis. An additional advantage of the studies presented is the inactivation of bacteria after a relatively short irradiation time (30 min), which does not often happen with photocatalysts not modified with noble metals. The modification methods presented represent a robust and inexpensive alternative to photocatalytic inactivation of bacteria. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride modified with kaolin-carboxyl graphene (g-C3N4/KG) was successfully synthesized using urea as the precursor and was applied for the photocatalytic degradation of pharmaceutical compound, "cefepime." Structural and optical characteristics of g-C3N4/KG were analyzed using various characterization techniques such as FT-IR, XRD, TEM, SEM, EDX, TG, BET, DRS, and PL. The PL studies confirmed that g-C3N4/KG catalyst exhibits strong charge separation and electron flow, and enhanced visible light absorption capacity was revealed by DRS studies. Studies on the active radical species demonstrate that superoxide and hydroxy radicals play a major role in the photocatalytic degradation of cefepime and dye pollutants. g-C3N4/KG showed the complete removal MB and 85% of degradation of cefepime under solar light irradiation time of 75 min and 135 min, respectively. Additionally, possible mechanism for the breakdown of the antibiotic cefepime was presented, along with identification of the intermediates produced during the degradation process. The study demonstrates that this novel photocatalyst could be utilized to remove dyes as well as medical wastes from water under solar light. [ABSTRACT FROM AUTHOR]

Perovskite oxides are attractive in the catalytic application owing to their stability, tuning characteristics, and easy synthesis process. Here, ZnTi 1-x Zr x O 3 (x = 0.5) (abbreviated as ZZT0.5) is synthesized under the chemical precursor solution decomposition method and calcined at 700 °C for 3 h. The cubic phase nanosized material exhibits cubic shape morphology with the proper ratio of the existing elements as from observed structural and morphological characterizations. In the photocatalytic dye degradation under natural sunlight irradiation, the materials show >90% color degradation of congo red and murexide. The observed result in the presence of solar light irradiation highlights an elevated photocatalytic efficiency. The pseudo-first-order degradation process shows a high correlation coefficient with good stability of the material in the reusable study. This ZnTiO 3 -based perovskite material has not been used previously in electrocatalytic water splitting. During oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) conditions, the material deposited on NF substrate showed 335 mV and 165 mV overpotential at 10 mA cm−2 current density, respectively which is indicative of notable electrocatalytic water splitting activity of the perovskite material designed herein. The long-term chronoamperometry (CA) study confirms the material's stability during both HER and OER conditions with negligible loss in activity over a period of 12 h. The post-catalytic characterizations confirm the robust nature of the material possessing the same phase characteristics. As an earth-abundant, low-cost material, the material designed herein shows the significant activity of environmental sustainability in terms of water treatment as well as green hydrogen production via electrolysis. [Display omitted] • Zr-doped ZnTiO 3 -based materials for photocatalytic & electrocatalytic study. • >90% color degradation for congo red and murexide under solar light. • OER and HER showed 335 mV and 165 mV overpotential at 10 mA cm−2 current density respectively. • The post-catalytic characterizations confirm the robust nature of the material. [ABSTRACT FROM AUTHOR]

The production of trifluoromethyl groups on organic compounds by graphene-based photocatalysts is an emerging research area in the 21st century. However, the pricey and poisonous nature of metal-based photocatalysts poses a significant barrier to the insertion of trifluoromethyl groups. Therefore, the trifluoromethylation of organic compounds and conversion into sustainable, greener chemicals via solar light irradiation is a hot and challenging topic. So, herein we developed a solar light-harvesting nitrogen enrich Eosin-Y functionalized graphene-based (NDGFE-Y) photocatalytic system with appropriate band gap and supported by UV-Visible, FTIR, XRD, and FE-SEM, Raman spectra and TGA curve. This prepared photocatalyst is a yardstick example for the photoinduced oxide CF3SO2Na to produce the CF3 as an electrophilic radical, effectively making the trifluoromethylation of benzaldehyde and their derivatives. The graphical abstract represents the highly selective NDGFE-Y photocatalyst for trifluoromethylation of Benzaldehyde under solar light irradiation. The NDGFE-Y photocatalyst has effective photocatalytic properties due to the functionalization of Eosin -Y dye. [ABSTRACT FROM AUTHOR]

Effective disinfection processes have been investigated to provide pathogen-free drinking water. Due to growing concern about the potential negative effects of cyanobacteria in portable water, their treatment has gained more attention recently. This study aims to compare the inhibition efficiencies of Gram-negative bacteria (Escherichia coli; E. coli), Gram-positive bacteria (Bacillus subtilis; B. subtilis), and cyanobacteria (Microcystis aeruginosa; M. aeruginosa) using UV-C and solar irradiation, and their combination process with H2O2. Over 6 log removal value (LRV) of E. coli and B. subtilis was achieved within 1 min of UV-C irradiation (0.76 ± 0.02 mW/cm2). The solar and solar/H2O2 (50 mg/L) processes effectively reduced (>99%) both bacteria after 20 min. E. coli was more sensitive to hydroxyl radicals (•OH) compared to the B. subtilis due to a different cell wall structure, resulting in a 0.18–0.62 higher LRV than B. subtilis. However, solar-based processes did not effectively inhibit M. aeruginosa (>52.23%). The UV-C/H2O2 (50 mg/L) process showed the highest inhibition rate for M. aeruginosa (77.83%) due to the generation of •OH, leading to oxidative damage to cells. Additionally, chlorophyll-a (Chl-a) was measured to indicate cell lysis of M. aeruginosa. The removal rate of Chl-a extracted by viable M. aeruginosa was higher using the UV-C process (93.03%) rather than the UV-C/H2O2 process (80.95%), because UV-C irradiation could be most effective in damaging Chl-a.

BiVO4 is an important n-type semiconductor used in photocatalysis due to its high capacity to absorb solar light in the 400–700 nm range, abundance, high chemical stability, non-toxicity, and low cost. However, research on physicochemical modifications to increase its catalytic activity via simple procedures is limited. In this work, the influence of different synthesis parameters, such as calcination temperatures or silver doping, on the structural and physicochemical characteristic of the BiVO4-based photocatalysts and their photocatalytic performance in degrading sulfamethoxazole from aqueous solution under blue-LED irradiation was evaluated. BiVO4-based photocatalysts were synthesized using a solvothermal method. The monoclinic phase (m-s) was successfully kept stable even after the thermal treatments at 300, 450, and 600 °C and the corresponding silver doping. The low bandgap of 2.40 eV and the average particle size of 18 nm of the BiVO4 catalyst treated at 300 °C seems to be the key. Afte doping, Ag/BiVO4 photocatalyst treated at the optimal found calcination temperature (300 °C) showed the best photocatalytic behavior.

In the present investigation, we have reported solar photo active, cost effective and magnetically recoverable magnesium substituted copper ferrites successfully prepared by simple co-precipitation method. The prepared materials were characterized for structural and microstructural analysis using PXRD, SEM, EDS, FT-IR and UV–Visible spectroscopy. It was observed that, when copper introduces into magnesium ferrite system light absorption shifted to visible region, this is due to formation of metastable energy levels just below the conduction band of magnesium ferrites. As a result an MgCuFe2O4 catalyst exhibits excellent efficiency under solar light irradiation. These catalysts are stable for longer period even after many runs and magnetically separable. Based on the analysis result these nanomaterials can be used as potential environmental and energy applications under natural sunlight irradiation.

Photocatalytic pure/sea water splitting driven by solar light, emerges as the most promising strategy to address both the global energy crisis and environmental degradation. Research efforts have mainly resulted in the development of artificial photocatalytic solar hydrogen generation systems applicable to both freshwater and sea water. During long‐term testing, sea water demonstrated enhanced stability compared to pure water, offering experimental advantages in designing novel techniques aimed at reducing hydrogen generation costs, alleviating freshwater scarcity, and optimizing the utilization of natural water resources. Moreover, sea water splitting proves to be more effective in producing solar hydrogen due to the potential sacrificial action of salt ions, which promote hydrogen evolution within the photocatalytic system. This review comprehensively outlines the fundamental principles of photocatalytic H2 production, examines the efficiencies and recent progress in hydrogen generation, explores the challenges faced, and envisions the future prospects of enhancing hydrogen production efficiency and reactivity through photocatalytic pure/sea water splitting. [ABSTRACT FROM AUTHOR]

In recent years, studies on the efficient spatial charge separation for broad solar light absorption and water remediation have been a major priority. Moreover, the development of transition metal-doped nanocomposites for this purpose is a new endeavor in current research. Here, we constructed an Fe3+-doped CdO/ZnS nanocomposite with a low doping level and investigated the effect of doping on the charge transfer and recombination behavior for improved photocatalytic performance. The X-ray diffraction analysis results indicate that both materials, CdO and ZnS, exhibit a cubic phase structure with an average crystallite size of 35 nm. Morphology analysis of the Fe3+-doped CdO/ZnS nanocomposite confirms the formation of irregularly shaped particle-like structures. From the optical studies, the bandgap energies of CdO/ZnS and Fe3+-doped CdO/ZnS nanocomposites are 3.19 eV and 2.87 eV, respectively, which proved that the iron ions doping reduced the bandgap energy and extended the absorption to the visible range. The efficiency of photodegradation in the tested samples was evaluated using tetracycline under solar light exposure. The experimental results demonstrated that the Fe3+-doped CdO/ZnS nanocomposite outperformed the other samples, exhibiting a significantly higher photocatalytic activity. After 80 min, it achieved a remarkable degradation rate of 97.06%. The Fe3+-doped CdO/ZnS nanocomposite demonstrated good stability and recyclability after five cycles. Radical trapping experiments showed that hydroxyl (•OH) radicals play a key role in photodegradation. [ABSTRACT FROM AUTHOR]

LaCoO3 elaborated by nitrate route was characterized physically and electrochemically to be applied in the Orange II (OII) oxidation upon solar light. The X-ray diffraction (XRD), SEM analysis and electrical conductivity were undertaken. The diffractogram showed that the single phase is completed at 850 °C and the oxide crystallizes in a distorted perovskite structure. The peak at 643 cm−1 in the attenuated total reflection (ATR) spectrum confirmed the purity of the phase. The forbidden band (1.35 eV), determined from the diffuse reflectance, is assigned to Co3+: d-d transition in a low spin configuration (3d6, E5/2) in conformity with the black color of the oxide. The field-dependent magnetization was measured at 300 K in the range ± 25 kOe, and the perovskite exhibits a low magnetism with a saturation magnetization (0.28 emu/g) confirming the low spin state Co3+. The thermal variation of the conductivity is characteristic of non-degenerate behavior and a hole mobility of 10−2 cm2 V−1 s−1 and an activation energy of 0.11 eV. The latter is different from that obtained from the thermo-power, a signature of a conduction mechanism by small polaron hopping. LaCoO3 is chemically stable above pH 5; an exchange current density of 40 μA cm−2, a polarization resistance of 1.92 kΩ cm2 and a corrosion potential of 0.99 VSCE were obtained at pH ~ 7 (Na2SO4, 0.1 M). Curiously and unlike the perovskites, the variation of the inverse of the square of the capacitance as a function of potential (C−2 − E) indicates p type behavior with a flat band potential of 0.30 VSCE and holes density of 1.97 × 1017 cm−3. The conduction band (− 0.94 VSCE), made up of Co3+: 3d orbital, enables the formation of the radical O2•−, and as application, the oxide was successfully experimented for the oxidation of OII upon solar irradiation. The hetero-junction p-LaCoO3/n-ZnO enhances considerably the photo-activity, due to the facile transfer of electrons with an abatement of 86% at neutral pH. The oxidation follows a first-order kinetic with a half photocatalytic life of 23 min. [ABSTRACT FROM AUTHOR]

Floating immobilized spherical titanium dioxide catalysts were used to degrade micro-pollutants by solar photocatalysis. The degradation of the micro-pollutants was performed in the secondary effluent of a wastewater treatment plant. During the experimental period, the continuous measurement of the solar ultraviolet (UV) radiation intensity was performed. The micro-pollutants were degraded to an average of 55% after 9 h of irradiation. A substance-specific degradation affinity was found, whereby degradation rates varied by a factor of up to 3.5. The substance-specific adsorption behavior was identified as a major limitation of the reaction performance. With an increasing influence of adsorption limitation, the degradation kinetics changed from the pseudo-first order to pseudo-zero order. A correlation between degradation rate and solar irradiance could only be found for substances with high degradation/adsorption affinity. For diclofenac, a 95% degradation rate could be achieved at a radiation dose of approximately 190 mWh/m². The investigated technology represents a promising possibility for a minimally invasive extension of wastewater treatment plants. Possibilities of implication were estimated and discussed within this work, whereby possibilities arise for large-scale as well as decentral treatment plants. HIGHLIGHTS Novelty floatable TiO2 catalysts for the micro-pollutant treatment in wastewater.; Evaluation of reaction rates of micro-pollutants during solar photocatalysis.; Correlation of individual reaction rate constants to measured UV-A radiation.; Extrapolation of the cleaning performance of the micro-pollutant removal process.;

0.5Ba (Zr0.2Ti0.8)O3-0.5(Ba0.7Sr0.3)TiO3 (BST-BZT) ceramic composition is known for exihibiting electrical properties. The present study brings out the prospective approach of utilizing well known BST-BZT ceramic composition for water cleaning application via piezocatalysis, photocatalysis and piezo-photocatalysis process. For this, BST-BZT ceramic composition was synthesized through solid state route reaction method and was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Methylene Blue (MB) a cationic dye was used as a representative organic pollutant, where the maximum degradation was observed in piezo-photocatalysis process (∼92%) followed by photocatalysis process (∼82%) and piezocatalysis process (∼65%) in 240 min. Furthermore, the degradation of MB dye was examined under solar light irradiation in order to assess the potential of the BST-BZT ceramic composition. A study on the BST-BZT ceramic composition's photocatalytic activity in an indoor setting was also conducted. Finally, the phytotoxicity level of “Vigna radiata” seeds was examined to determine the extent of MB dye breakdown and its subsequent usage.