Molecular dynamics of stability and structures in phytochelatin complexes with Zn,Cu, Fe,Mg, and Ca: Implications for metal detoxification

Phytochelatins, or (γ-glutamyl-cysteine) _n -glycine, are specialized peptides produced by plants and algae to mitigate toxic metal exposure, for instance in response to high levels of metals such as Cu, Cd, and Zn. Stability constants and structural characterization of metal–phytochelatin complexes are lacking. This information is required to gain mechanistic insights on the metal selectivity of phytochelatins. Here, we studied structural coordination and thermodynamic stability by performing molecular dynamics simulations of a fully hydrated phytochelatin molecule complexed with Ca²⁺, Mg²⁺, Fe²⁺, Zn²⁺, and Cu²⁺. Our results predict the following decreasing order for the thermodynamic stability of the phytochelatin complexes: Zn²⁺ ≥ Cu²⁺ ≥ Fe²⁺ > Mg²⁺ > Ca²⁺. The favorable binding energies with Zn²⁺ and Cu²⁺ over the other metal cations can be explained by shorter binding distances and greater coordination from carboxylate and keto O atoms. Conformational rearrangement of phytochelatin following metal chelation was captured by monitoring changes in the solvent-accessible volume. Accessibility of solvent molecules to the phytochelatin structure was inversely proportional to the distance between the coordinated ligands and the chelated metal. These new findings demonstrate the influence of the metal–phytochelatin structure on the metal-binding thermodynamics and the phytochelatin conformation, both of which are important to evaluate the intracellular role of phytochelatin in mediating algal response to toxic heavy metal exposure.     

Removal of metal ions from aqueous solution by chelating polymeric hydrogel

Polysaccharide natural seed coat from the tree Magonia pubescens, in the form of hydrogel was used to remove metals in aqueous solution. Swelling tests indicate that seed coat presents hydrogel behavior, with maximum water absorption of 292 g water/g. Adsorption experiments performed using Na⁺, Mg²⁺, K⁺, Ca²⁺, Cr³⁺, Fe³⁺ and Zn²⁺ demonstrated that the polysaccharide structure has a high capacity to extract these ions from the aqueous solution. Scanning electron microscopy revealed significant morphological changes of the material before and after water contact. Differential scanning calorimetry measurements indicate a signal shift of the water evaporation temperature in the material with adsorbed zinc. X-ray photoelectron spectroscopy analysis combined with theoretical studies by the density functional theory and on Hartree–Fock (HF) level evidence that the metallic ions were adsorbed through coordination with hydroxyl groups of polysaccharide. In the case of Zn²⁺ the lowest HF energy was observed for the tetracoordination mode, where Zn²⁺ is coordinated by two hydroxyl groups and two water molecules.     

Application of Zr(IV) tungstate for removal of metal ions from aqueous solutions

A heteropolyacid Zr(IV) tungstate-based cation exchanger has been synthesized. An amorphous sample, prepared at pH 1.2 and having a Na⁺ ion exchange capacity of 0.92?meq?g^?1, was selected for further studies. Its physicochemical properties were determined using Fourier transform infrared spectrometer, X-ray diffraction, thermogravimetric, and scanning electron studies. To understand the cation exchange behavior of the material, distribution coefficients (K _d) for metal ions in various solvent systems were determined. Some important binary separations of metal ions, namely Mg²⁺–Bi³⁺, Cd²⁺–Bi³⁺, Fe³⁺–Bi³⁺, Th⁴⁺–Bi³⁺, and Fe³⁺–Zn²⁺, were achieved on such columns. The practical utility of these separations was demonstrated by separating Fe³⁺ and Zn²⁺ ions quantitatively in commercial pharmaceutical formulation. The cation exchanger has been successfully applied also for the treatment of industrial wastewater and a synthetic mixture. All the results suggests that Zr(IV) tungstate has excellent potential for the removal of metals from aqueous systems using packed columns of this material.     

Capacity of simultaneous removal of zinc and cadmium from contaminated media, by two microalgae isolated from a polluted site

Several aquatic environments have been contaminated with heavy metals dumped via industrial effluents. Numerous studies have been published regarding the removal of single metals from aqueous solutions by microalgal biomass. However, such studies do not reflect the actual problem associated with industrial effluents because usually more than one metal species is present. Here we studied the biosorption capacity of Zn²⁺ and Cd²⁺ as single- and binary-metal systems by two microalgae, Scenedesmus obliquus and Desmodesmus pleiomorphus, isolated from a polluted site in Northern Portugal. For each metal independently, D. pleiomorphus showed a higher metal sorption capacity than S. obliquus, at concentrations ranging from 60 to 300 mg/l (except 150 mg_Cd/l). Maximum amounts of Zn²⁺ and Cd²⁺ removed were 22.3 and 60.8 mg/g by S. obliquus, and 83.1 and 58.6 mg/g by D. pleiomorphus. In binary-metal solutions, S. obliquus was in general able to remove Zn²⁺ to higher extents than Cd²⁺, whereas the opposite was observed with D. pleiomorphus. The simultaneous uptake of Zn²⁺ and Cd²⁺ by both microalgae was considerably lower than that of their single-metal counterparts, at equivalent concentrations. Although microalgal uptake from binary-metal solutions was lower than from single-metal ones, the wild microalgae selected were able to efficiently take up mixtures of Zn²⁺ and Cd²⁺ up to 300 mg/l of both metals—thus materializing a promising bioremediation vector for polluted waters.     

Effects of cadmium on intracellular cation homoeostasis in the yeast Saccharomyces cerevisiae

Previous studies have demonstrated that cadmium can induce biochemical and physiological changes in yeast Saccharomyces cerevisiae. However, studies on the influence of cadmium on the ion balance in the cell and the interaction between cadmium and other ions are still relatively few in number. By using inductively coupled plasma-atomic emission spectrometry, the contents of some cations, including Zn²⁺, Ca²⁺, Fe³⁺, Cu²⁺, Mg²⁺, K⁺, and Na⁺ were measured. The data showed that the levels of Zn²⁺ and Fe³⁺ were increased, while those of Cu²⁺, K⁺, and Na⁺ were decreased after cadmium treatment. Afterwards, using the drop test assay, the interactions between cadmium and the selected ions were investigated. The results suggested that the cytotoxicity of cadmium could be attributable to the interference of cadmium with the intracellular cation homoeostasis. Calcium channel transporter Cch1 participates in the intracellular uptake of cadmium. Additionally, Zn²⁺, Ca²⁺, Fe³⁺, Mg²⁺, and K⁺ can rescue the toxic effect of cadmium in yeast.     

Comparative phytotoxicity of ZnO nanoparticles,ZnO microparticles,and Zn2+ on rapeseed (Brassica napus L.): investigating a wide range of concentrations

The effects of ZnO nanoparticles (NPs), ZnO microparticles (MPs), and zinc ions (Zn²⁺) on some growth parameters of rapeseed (Brassica napus) seedlings have been studied. The growth inhibition by ZnO NPs was not stronger than that by ZnO MPs while treatment with Zn²⁺ inhibition was clearly stronger.     

The nature of zinc and copper complexes in the oyster Ostrea edulis

The zinc and copper associated with the soft tissues of the oyster Ostrea edulis Linnaeus have been separated into a soluble component and a tissue-residue, cell-debris bound component. In the case of zinc, the tissue-bound component was found to contain at least two species of complex; a firmly-bound species, exchangeable with ⁶⁵Zn²⁺ and a less-firmly, reversibly-bound species, exchangeable with ⁶⁵Zn²⁺. The soluble component, which constitutes some 40% of the total zinc and copper, was fractionated on Sephadex G-25 and the zinc and copper shown to be weakly-complexed to the small molecular weight compounds, taurine, lysine, ATP and possibly homarine (N-methyl--picolinic acid) and to be fully exchangeable with ⁶⁵Zn²⁺. These soluble complexes can act as a freely available mobile reserve of metal to ensure a constant saturation of metal-dependent enzyme systems operating under adverse environments. Sephadex G-25 acts as a weak ion-exchange resin, which can cause a translocation of zinc and copper from its soluble weak complexes and result in the spurious association of the metals with other compounds.     

Release of ultraviolet-absorbing compounds by the red-tide dinoflagellateLingulodinium polyedra

We tested the hypothesis that ultraviolet-absorbing compounds known as mycosporine-like amino acids (MAAs) are not only synthesized but also excreted by marine phytoplankton. An experiment was performed with cultures of the marine dinoflagellateLingulodinium polyedra (previously known asGonyaulax polyedra) exposed to visible (photosynthetically available, PAR, 400 to 700 nm) and ultraviolet (UV, 290 to 400 nm) radiation. Absorption properties of both particulate and dissolved organic matter pools (POM and DOM, respectively) showed maxima in ultraviolet absorption at 360 nm. Chromatographic analysis confirmed the presence of MAAs in both pools. Release of organic matter byL. polyedra, as measured spectrophotometrically by changes in UV absorption in the surrounding medium, showed a differential increase at 360 nm in cultures exposed to UV-B + PAR radiation. The changes in absorption in the DOM fraction were inversely proportional to intracellular UV absorption. Photodegradation experiments in which the DOM fraction was exposed to visible and UV-B radiation showed a decrease in absorption with dose. First-order photooxidation decay rates varied between – 0.005 and – 0.26 m² (mol quanta)^–1 and were also a function of the initial optical density (OD). These results indicate that UV-absorbing compounds synthesized by phytoplankton, such as certain dinoflagellates, may be a component of the DOM pool in surface waters of the ocean and contribute to the attenuation of UV radiation in the water column. Photooxidation consumes only 3 to 10% of the daily production of the DOM absorbing between 280 and 390 nm (including MAAs). This suggests that MAAs dissolved in seawater may contribute to the decrease of UV transmission through the water column on a time scale representative of phytoplankton growth (days) and bloom development (weeks).     

细颗粒物(PM_(2.5))主要组分模拟溶液对发光细菌的光抑制分析

为明确NH_4~+、 NO_3~-、SO_4~(2-)及金属等组分在水溶性提取液对发光细菌的光抑制过程中所起的作用,参照PM_(2.5)样品提取液浓度,模拟配制与3级以上PM_(2.5)样品提取液中主要组分:硫酸盐、硝酸盐、氨盐相同浓度的溶液,同时选取与PM_(2.5)可溶性提取液发光抑制率相关性较强的铅、锌,配制不同浓度级别模拟溶液,测试各单一组分对发光细菌的发光抑制率及其混合溶液对发光细菌的联合影响效应。基于毒性单位法(TU)、相加指数法(AI)和混合毒性指数法(MTI)评价了混合体系联合影响的作用类型。结果表明,与3~6级PM_(2.5)可溶性提取液中硫酸氨、硫酸氢氨、硝酸氨、硫酸锌和硝酸铅浓度相同的模拟溶液对发光细菌的发光没有抑制作用。不同的评价方法对PM_(2.5)主要组分混合体系联合效应评价结果具有较好的一致性,硫酸氨、硝酸氨、硫酸氢氨混合溶液中,对发光细菌的光抑制均为硫酸氢氨的独立作用,硫酸锌与硝酸铅的混合体系,锌和铅对发光细菌的联合影响效应表现为协同,硫酸氨、硝酸氨、硫酸氢氨与硫酸锌、硝酸铅的多元混合体系呈现协同作用。     

Polarographic investigations on the complexation of cadmium and zinc by thiol peptides

Complex formation of Cd²⁺ and Zn²⁺ with thiol derivatives has been investigated by differential pulse polarography. The binding of Cd²⁺ and Zn²⁺ with cysteine (CySH), glutathione (GSH) and the model peptide N‐acetyl‐cysteine‐methylamide (ASH) reveals different stoichiometry. Thus, Cd²⁺ forms 1:1 and 1:2 complexes with CySH while 1:2 and 1:4 complexes have been observed with GSH and ASH, respectively. Overall formation constants of Cd²⁺ with CySH (Iogβ ₂ 15.3) and with GSH (Iogβ5₂ 14.4) have been estimated using competitive complexation with nitrilotriacetic acid (NTA). Investigation of competition between Zn²⁺ and Cd²⁺ for the thiol complexation has underlined the role played by the amino group in CySH for the stabilization of Zn complexes in contrary to Cd complexes.     

Trends in precipitation chemistry in Alaska, 1980–1998

Nineteen years (1980–1998) of precipitation chemistry data from a site in Alaska are examined for trends using a least squares general linear model. The annual concentrations of SO^2– ₄ show a significant decreasing trend at 0.001 level and the annual change in concentration is —0.012mg 1^–1 yr^–1. The annual concentrations of NO ^– ₃ show an increasing tendency non‐significant. The annual base cation concentrations show a clear significant decreasing trend at 0.001 level and the decrease is —0.009mg 1^–1 yr^–1. Ca²⁺ concentrations exhibit a significant decreasing trend at 0.001 level and the annual change of concentration is —0.003 mg 1^–1 yr^–1. Mg²⁺ and Na⁺ concentrations show a significant decreasing trend at 0.01 level and the annual change is —0.001 mg1^–1 yr^–1 for Mg²⁺ and —0.004 mg1^–1 yr^–1 for Na⁺. K⁺ concentrations are characterised by a decreasing trend, significant at 0.05 level. K⁺ concentrations have decreased —0.002mg1^–1 yr^–1. The strongest rates of concentration decline for base cations, Ca²⁺, Mg²⁺, K⁺ and Na⁺ occurred in fall and winter season. The annual values of pH show a decreasing trend non‐significant. The values of pH oscillate between 5.1 and 5.6 during the period considered.     

Geochemistry and quality of groundwater of the Yarmouk basin aquifer,north Jordan

Quality of groundwater in the Yarmouk basin, Jordan has been assessed through the study of hydrogeochemical characteristics and the water chemistry as it is considered the main source for drinking and agriculture activities in the region. The results of the relationship between Ca²⁺ + Mg²⁺ versus HCO₃^? + CO₃^2?, Ca²⁺ + Mg²⁺ versus total cations, Na⁺ + K⁺ versus total cations, Cl^? + SO₄^2? versus Na⁺ + K⁺, Na⁺ versus Cl^?, Na⁺ versus HCO₃^? + CO₃^2?, Na⁺ versus Ca²⁺, and Na⁺: Cl^? versus EC describe the mineral dissolution mechanism through the strong relationship between water with rocks in alkaline conditions with the release of Ca²⁺, Mg²⁺, Na⁺, K⁺, HCO₃^?, CO₃^2?, SO₄^2?, and F^? ions in the groundwater for enrichment. Furthermore, evaporation processes, groundwater depletion, and ion exchange contribute to the increased concentration of Na⁺ and Cl^? ions in groundwater. Anthropogenic sources are one of the main reasons for contamination of groundwater in the study area and for increasing the concentration of Mg²⁺, Na⁺, Cl^?, SO₄^2?, and NO₃^? ions. Results show the quality of groundwater in the study area is categorized as follows: HCO₃^? + CO₃^2? > Cl^? > SO₄^2? > NO₃^? > F^? and Na⁺ > Ca²⁺ > Mg²⁺ > K⁺. In conclusion, the results of TDS, TH, and chemical composition showed that 26% of the groundwater samples were unsuitable for drinking. About 28% of groundwater samples in the study area have a high concentration of Mg²⁺, Na⁺, and NO₃^? above the acceptable limit. Also, based on high SAR, 10% of the groundwater samples were not suitable for irrigation purposes.     

Oxidized multiwalled carbon nanotubes modified with 2-(2-hydroxy-5-nitrophenyl)-4,5-diphenyl imidazole for solid phase extraction and preconcentration of some metal ions

In this work, a new procedure for the enrichment of the trace amount of Cu²⁺, Ni²⁺, Co²⁺, Pb²⁺, Fe²⁺, and Zn²⁺ ions based on the utilization of multiwalled carbon nanotubes (MWCNT) modified with 2-(2-hydroxy-5-nitrophenyl)-4,5-diphenyl imidazole as chelating agent prior to their determination by flame atomic absorption spectrometry has been described. The influence of effective parameters including pH, amount of ligand and MWCNT, composition of eluent, and coexisting ions on recoveries of understudy metal ions was examined. At the optimum pH of 5.0, all metal ions were quantitatively sorbed onto the proposed solid phase and completely desorbed with 8?mL of 5.0?mol?L^?1 HNO₃. The detection limit of Cu²⁺, Co²⁺, Ni²⁺, Pb²⁺, Fe²⁺, and Zn²⁺ ions was 1.7, 2.4, 2.3, 2.9, 2.8, and 1.4?µg?L^?1, while the preconcentration factor was 63 for Cu²⁺ and 94 for the other metal ions and relative standard deviations between 1.8 less than 3.0%. The proposed procedure was applied for the analysis of various samples.     

Effect of salinity fluctuation on the osmotic pressure and Na+, Ca2+ and Mg2+ ion concentrations in the hemolymph of bivalve molluscs

Specimens of Chlamys opercularis, Modiolus modiolus, Mytilus edulis, Crassostrea gigas, Scrobicularia plana and Mya arenaria were exposed to both gradual (sinusoidal) and abrupt (square-wave) salinity fluctuations and measurements made of osmotic, Na⁺, Mg²⁺ and Ca²⁺ concentrations in the hemolymph and where applicable in the mantle fluid. In both sinusoidal and square-wave regimes fluctuating between 100 and 50% seawater (100%=ca. 32 S), the hemolymph Na⁺, Mg²⁺, Ca²⁺ and osmotic concentrations followed the concentrations of the external medium in Chlamys opercularis. The hemolymph and mantle fluid osmotic Na⁺, Mg²⁺ and Ca²⁺ concentrations of Modiolus modiolus, Mytilus edulis, Crassostrea gigas and S. plana followed those of the external medium as long as the molluscs' shell valves remained open. There were no changes in the ionic or osmotic concentrations of the hemolymph or mantle fluid of any of these species during periods of shell-valve closure. The hemolymph osmotic, Na⁺ and Mg²⁺ concentrations of wedged-open Modiolus modiolus, Mytilus edulis, C. gigas and S. plana followed those of the external medium. Hemolymph Ca²⁺ concentrations showed a damped response in C. gigas and Mytilus edulis. The hemolymph osmotic, Na⁺, Ca²⁺ and Mg²⁺ concentrations of Mya arenaria fluctuated in a similar manner to the external medium, but were damped. Wedged-open Mytilus edulis exposed to fluctuating salinity and supplied with a constant supply of 10 mM Ca²⁺ showed greater changes in hemolymph ionic and osmotic concentrations than M. edulis exposed to the same salinity fluctuation without a constant Ca²⁺ supply. Chlamys opercularis and Modiolus modiolus survived in a 50% seawater minimum sinusoidal salinity fluctuation for 10 days; wedged-open M. modiolus survived only 3 days. Burrowing had no effect on the osmotic, Na⁺, Mg²⁺ or Ca²⁺ concentrations of the hemolymph of Mya arenaria or S. plana exposed to fluctuating salinities. All of the species studied were shown to be osmoconformers.     

Adsorptive behaviors of humic acid onto freshly prepared hydrous manganese dioxides

This study focused on the adsorptive behaviors of humic acid onto freshly prepared hydrous MnO₂(s) (δMnO₂), and investigated the feasibility of employing δMnO₂ for humic acid removal from drinking water. Effects of such parameters as molecular mass of humic acid, kinds of divalent cations on adsorptive behaviors and possible mechanisms involved were investigated. This study indicated that humic acid with higher molecular mass exhibited more tendency of adsorbing onto δMnO₂ than that with lower molecular mass. Ca²⁺ facilitated more humic acid adsorption than Mg²⁺; UV-Vis spectra analysis indicated higher capabilities of Ca²⁺ coordinating with acidic functional groups of humic acid than that of Mg²⁺. Additionally, ζ potential characterization indicated that Ca²⁺ showed higher potential of increasing gz potential of δMnO₂ than Mg²⁺. Ca²⁺ of 1.0 mmol/L increased ζ potential of δMnO₂ from ?37 mV (pH 7.9) to +7 mV (pH 7.2), while 1.0 mmol/L Mg²⁺ increased to lower value as ?9 mV (pH 6.5), correspondingly. Fourier transform infrared (FTIR) spectra demonstrated the adsorption of humic acid onto δMnO₂, showing the important roles of-COO^? functional groups and surface Mn-OH in the adsorption of humic acid onto δMnO₂.     

Toxic effects of dietary of Al3+ ions in tilapias (Oreochromis niloticus) and protective effect of Zn2+ ion

The lethal effects of aluminum ion (Al³⁺) in tilapia (Oreochromis niloticus) raised in concrete tanks were investigated. Tilapias were fed daily with commercial feed enriched with known concentrations of Al³⁺ and analyzed by differential pulse anodic stripping voltammetry (DPASV). The concentrations of Al³⁺ in feces, water, muscle tissue, viscera, and heads were determined every 3 months for a period of 365 days. The Tilapia head was the most affected tissue by Al³⁺. In general, Al³⁺ bioaccumulation reached the lethal dose (LD₅₀) after 335 days of experiment as follows: 34.9?mg?kg^?1 (muscle tissue), 88.2?mg?kg^?1 (viscera), and 126.9?mg?kg^?1 (head without gills). After determining Cu²⁺, Zn²⁺, and Ca²⁺ by absorption spectrometry, a decrease in the Ca²⁺ concentration was noted in the head during the experimental period. These observations were associated with the occurrence of a decalcification in the bone tissue in the presence of Al³⁺. In contrast, it was found that Zn²⁺ ions may act as a protective agent against Al³⁺-induced contamination.     

Photocatalytic degradation of chlorophenols using Ru(bpy) 3 2+ /S2O 8 2−

Advanced oxidation processes, such as photocatalysed oxidation, provide an important route for degradation of wastes. In this study, the lowest excited state (³MLCT) of Ru(bpy)₃²⁺ is used to break down chlorophenol pollutant molecules to harmless products. This has the advantage of using visible light and a short-lived catalytically active species. Photolysis of deaerated aqueous solutions of a variety of mono- and poly-substituted chlorophenols has been followed in the presence of Ru(bpy)₃²⁺/S₂O₈²⁻ with near visible light (λ > 350 nm) by UV/visible absorption spectroscopy, luminescence, potentiometry, NMR and HPLC techniques. Upon irradiation, a decrease is observed in the chlorophenol concentration, accompanied by the formation of Cl⁻, H⁺ and SO₄²⁻ ions as the main inorganic products. Benzoquinone, phenol, dihydroxybenzenes and chlorinated compounds were the dominant organic products. As the ruthenium(II) complex is regenerated in the reaction, the scheme corresponds to an overall catalytic process. The kinetics of the rapid chlorophenol photodechlorination has been studied, and are described quite well by pseudo-first order behaviour. Further studies on this were made by following Cl⁻ release with respect to the initial Ru(bpy)₃²⁺ and S₂O₈²⁻ concentrations. A comparison is presented of the photodechlorination reactivity of the mono and polychlorophenols studied at acidic and alkaline pH.     

Removal of Zn2+ from aqueous solution by biomass of Agaricus bisporus

Biosorption of Zn²⁺ from aqueous solutions by biomass of Agaricus bisporus was investigated. The removal rates of Zn²⁺ by A. bisporus under different parameters (e.g., solution pH, bio-sorbent dosage and initial Zn²⁺ concentration) were studied. The inhibition of A. bisporus’s biosorption by anionic ligands EDTA (Ethylene Diamine Tetraacetic Acid), acetate and citrate) implied that EDTA and citrate might be used as eluting reagents. Regular and simultaneous solution pH change and light metal ions release after biosorption indicated that an ion exchange mechanism was involved. From FT-IR (Fourier Transform Infrared) spectroscopy, the main functional groups participated in biosorption were found. Biosorption of Zn²⁺ by A. bisporus could be well described by the Freundlich and Langmuir models. In conclusion, the biomass of A. bisporus showed high potential for the treatment of wastewater containing Zn²⁺.     

Green synthesis and characterization of metal ions-mixed titania for application in dye-sensitized solar cells

Abstract

The objective of the present study is to synthesize various metal ions mixed TiO₂ nanoparticles using a continuous hydrothermal synthesis pilot reactor for dye-sensitized solar cells (DSCs). In the pilot plant, aqueous solutions of the metal salts are mixed with a flow of supercritical water (450?°C and 24.1?MPa) in a confined jet mixer for continuous synthesis of metal ions-mixed nano-titania. Characterization of the particles was made using Brunauer–Emmett–Teller technique for specific surface area, powder X-ray diffraction analysis and transmission electron microscopy for identification and crystallite size, X-ray photoelectron spectroscopy for surface analysis and infrared spectroscopy for distinct group identification. Following the already existing procedures and using the titanates synthesized, dye-sensitized cells of 1?cm² area were assembled and their photovoltaic parameters were evaluated under standard test conditions. The power conversion efficiencies (η %) for 40?mol % Zn²⁺, 5?mol % Zr⁴⁺ and 10?mol % Zn⁴⁺ titania were obtained to be 4.8, 4.95 and 4.9, respectively. The promising efficiency results from a greener and large-scale production of nano-titania is a step forward towards commercializing DSC technology.