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In this article, the direct electrochemical behavior of nitrite at a Au nanoparticles (AuNPs)/carbon paper (CP) electrode made using a rapid electrochemical deposition method was investigated. The morphology of the AuNPs on the CP surface was characterized by scanning electron microscopy (SEM). The existence of the Au element was verified by energy dispersive spectroscopy (EDS). The crystal structure of the AuNPs was verified by X-ray diffraction (XRD). Cyclic voltammetry (CV) was applied to evaluate the electrochemical behavior of nitrite oxidation. Under the optimum conditions, the AuNPs/CP electrode exhibited a very strong response to nitrite; the oxidation peak current linearly increased with increasing nitrite in the ranges of 1 μM to 30 μM and 40 μM to 100 μM with correlation coefficients of 0.99883 and 0.99789, and a low detection limit of 0.093 μM. The suggested sensor demonstrated high sensitivity, good reproducibility and good recovery. [ABSTRACT FROM AUTHOR]

Chiral surfaces are an object of interest due to their application in catalysis, separation and sensors. Such surfaces can exhibit chirality on the molecular or supramolecular level. Previously, we have studied the thermodynamic features of adsorption on non-porous surfaces with supramolecular chirality. However, for their application in enantiomer separation, enantioselectivity and capacity should be greater. Porous adsorbents are promising for this purpose. In this work, the enantioselectivity of copper borophosphate LiCu2[BP2O8(OH)2] was studied. This zeotype material was obtained by hydrothermal synthesis without any source of chirality. Supramolecular chirality was achieved by spontaneous symmetry breaking via Viedma ripening. XRD and SEM were used to prove the synthesis accuracy. Enantioselectivity during adsorption was studied using the adsorption isotherms of α-pinene and limonene enantiomer analysis. The experimental isotherms were approximated by Langmuir, Dubinin–Radushkevich, Freundlich and Fowler–Guggenheim equations. The t-test was used to prove the reliability of the differences in enantiomer adsorption. The isosteric heats of adsorption were calculated from the adsorption isotherms. The data obtained have shown the ability of the LiCu2[BP2O8(OH)2] surface to recognize both α-pinene and limonene enantiomers. The molecules of α-pinenes adsorbed without pores, with the maximum enantioselectivity coefficient of 1.23 at 80 °C. Limonene molecules adsorbed in pore volume as single molecules or 1D chains. This phenomenon was proved by analysis of isosteric heats. The enantioselectivity of copper borophosphate to limonenes and α-pinenes was similar. The ability of pores with supramolecular chirality (and without molecular chirality) to recognize enantiomers was discovered in this paper for the first time. [ABSTRACT FROM AUTHOR]

This study presents an electrochemical procedure for synthesizing graphene oxide (GO) nanosheets in a diluted acidic medium (0.05 M), featuring 100% synthesis yield. Characterization results revealed that the synthesized GO in this approach exhibits a low XRD peak position (around 10°) and a C/O ratio of 2.9, offering higher surface functionality than conventional electrochemical methods reported in the literature. We also demonstrated the tunability of the GO's surface functionality by manipulating the synthesis parameters, such as electrolyte concentration and synthesis time, offering flexibility that surpasses the constraints often seen in chemical methods. Additionally, it was observed that assembling the current GO nanosheets into diverse microscopic (e.g., layered and porous) and macroscopic (e.g., paper and aerogel) structures results in distinctive characteristics and properties. Electromagnetic interference (EMI) shields with tunable specific EMI shielding effectiveness (SSE/t) and shielding mechanisms have been devised by fine-tuning the synthesis and processing methodologies. Excellent SSE/t ranging from 5000 dB cm2 g−1 for compact to 2000 dB cm2 g−1 for porous shields has been achieved, unraveling the importance of multi-scale materials design for the performance of the final products. [ABSTRACT FROM AUTHOR]

In this paper, in order to solve the problem of more impurities and less functional groups on the surface of sludge-based biochar, phosphoric acid and chitosan were used to co-modify sludge-based biochar (CS/SBC-H3PO4) to enhance the removal of Cr(VI). CS/SBC-H3PO4 was characterized using SEM, XRD, FT-IR spectroscopy and XPS. When the initial concentration of Cr(VI) solution was 100 mg L−1, the pH was 2.0, and the dosage of adsorbent was 50 mg, the Cr(VI) removal rate of CS/SBC-H3PO4 was 89.70%. The adsorption process of Cr(VI) by CS/SBC-H3PO4 was spontaneous and heat-absorbing, and was dominated by monolayer chemisorption, which followed the quasi-second-order kinetic model and Langmuir adsorption isotherm model, and its maximum adsorption capacity was 201.93 mg g−1 at 298 K. The removal mechanism of Cr(VI) by CS/SBC-H3PO4 is electrostatic adsorption, reduction and complexation. In detail, CS/SBC-H3PO4 electrostatically adsorbs Cr(VI) through surface amino protonation, and then reduces Cr(VI) to Cr(III) through –NH3+ and O–H groups to generate –NO2, C–O and C＝O groups. Finally, Cr(III) is complexed with the C＝O group. [ABSTRACT FROM AUTHOR]

Rare-earth doped phosphors have received growing interest in the luminescence field, and hold great potential for lighting and display backlight applications. Nonetheless, the practical implementation of white light-emitting diodes requires the development of a cost-effective and high-performance red phosphor, which is still a significant challenge. In this paper, Eu3+ doped Ba3Na0.32Nb6O12(Si2O7)2 red phosphors were prepared using a high-temperature solid-state method. The structure and phase purity of the samples were analyzed in detail by powder X-ray diffraction (XRD), structure refinement and energy dispersive spectroscopy analysis. Under 395 nm excitation, the phosphor exhibited an intense red emission due to the 5D0 → 7FJ (J = 1, 2, 3, 4) transitions. Through decay curve measurements, it is found that the decay time corresponding to the double-exponential equation decreased with the increase of activator concentration. Theoretical calculations showed that the quadrupole–quadrupole interaction played a dominant role in concentration quenching. The CIE chromaticity coordinates of the phosphor were (0.6436, 0.3556) and the color purity reached 92.07%, indicating that the sample has high color purity. In addition, the temperature-dependent intensity was investigated in detail. The results demonstrated that Ba3Na0.32Nb6O12(Si2O7)2:Eu3+ is a potential red-emitting phosphor for near-ultraviolet based white light-emitting diodes. [ABSTRACT FROM AUTHOR]

In this paper, we report the synthesis methodology of a series of molybdate-intercalated hydrotalcite-like materials and their catalytic applications for the esterification of biomass-derived levulinic acid. A simple hydrothermal method was used to synthesize molybdate-intercalated MgFe, MgAl, and MgCr hydrotalcites in the presence of an ammonia solution as a hydrolyzing agent. The intercalation of molybdate was confirmed via X-ray diffraction (XRD) studies based on line broadening in the XRD pattern and peaks characteristic of a layered hydrotalcite structure with short-range ordering were observed. The introduction of the molybdate species resulted in strong Lewis-acidic sites, as evident from FT-IR pyridine desorption and temperature-programmed desorption studies. The resulting material exhibited a significant activity for the esterification of the biomass-derived levulinic acid. The reaction conditions were systematically optimized. The molybdate-intercalated magnesium iron hydrotalcite exhibited 93% conversion of levulinic acid to butyl levulinate (120 °C, 4 h) with 95% selectivity. Good recyclability of the catalysts was demonstrated using recyclability studies, in which the catalysts showed excellent stability and high conversion even after five cycles. [ABSTRACT FROM AUTHOR]

In this paper, a Co--Fe LDO catalyst was prepared by combining K2Cr2O7 and Cr(NO3)3 to modify the LDH precursor. The catalytic activity of NOx and o-DCB was systematically studied, and the effect of gas composition on the catalytic activity was investigated. The prepared Cr (0.25)/Co--Fe LDO catalyst showed the best catalytic performance, with conversion efficiencies of NOx and o-DCB of 89.0% and 81.6% at 250 °C, respectively. The catalysts were characterized by XRD, BET, SEM, XPS, H2-TPD and NH3-TPD to explore the reaction activity. In addition, the interaction between NH3-SCR and o-DCB oxidation was investigated by changing the gas atmosphere. The results showed that the inhibition at low temperature (< 200 °C) could be attributed to the residues of the by-products of incomplete oxidation. The further oxidation of NO to NO2, and the dissociation of NH3 are the reasons for the mutual promotion of the two reactions in the middle and high temperature sections. Water vapor has little effect on the reaction and the introduction of SO2 will cause irreversible inactivation of the catalyst. [ABSTRACT FROM AUTHOR]

In this paper, we report the synthesis of titanium dioxide nanoarrays (TNAs) via an anodization process using different counter electrodes, including Pt, Ni, Ti, Cu, Al, and graphite. The synthesized TNAs are studied as anode materials for lithium ion batteries. The crystallographic structure and surface morphology of the TNAs are studied using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). Electrochemical tests of the TNA-Li half-cells are carried out using cyclic voltammetry (CV), charge/discharge analysis, and electrochemical impedance spectroscopy (EIS). These results show that the TNA morphologies and crystallography strongly depend on the type of counter electrode. The synthesis of TNAs using Pt and Al as a counter electrode leads to the highest and lowest crystal growth in the preferred 001 direction, respectively, in comparison with other counter electrodes. The TNAs anodized using a Pt counter electrode illustrate an acceptable cyclability and rate capability up to 100 cycles. [ABSTRACT FROM AUTHOR]

The present paper discusses the role of calcination in tuning the non-enzymatic glucose sensitivities of Cu–Ni bimetallic nanocomposites. Nanoparticles of Cu, a layered hydroxide of Ni and Cu–Ni nanocomposites were synthesized via the polyol reduction method. The prepared nanomaterials were thoroughly characterized by X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDS). Thermogravimetric analysis (TGA) was done in order to understand the thermal behavior of the nanoparticles. The prepared nanomaterials were subjected to calcination at three different temperatures viz. 400, 500 and 600 °C. The non-enzymatic glucose sensing activity of the nanomaterials was studied electrochemically. The nanocomposites showed the best sensing performance among the prepared nanomaterials. Interestingly, calcination resulted in a seven-fold increase in the sensitivity of the nanocomposites. The nanocomposite that was calcined at 600 °C showed the maximum sensitivity of 63.87 μA mM−1 cm−2 with a low detection limit of 8 μM at a signal to noise ratio of 3. The nanocomposite showed a distinct linear response in the range of 0.01 to 18 mM with a regression coefficient of 0.99162. The nanocomposite also exhibited excellent selectivity for glucose in the presence of other interfering agents. The nanocomposite also demonstrated good agreement with the pathology laboratory data for whole blood and blood serum samples. [ABSTRACT FROM AUTHOR]

This paper describes the consequences of incorporating a constrained heterocyclic aromatic β-amino acid 3-aminothiophenecarboxylic acid (3-Atc) into peptides containing β-turn forming elements such as Pro-Gly motif and the effect on the secondary structural architecture of the entire peptide backbone. Conformational investigations of oligomers comprising an α,β,α peptide sequence were carried out by single-crystal X-ray diffraction, solution-state NMR, nOe-restrained MD simulation and circular dichroism studies. The results suggested that these peptide sequences assume helical architecture. The helical folding in the oligomers was found to be devoid of inter-residual H-bonding, instead found to be stabilized by a co-operative effect of 6-membered H-bonding within the 3-Atc unit and conformational restrictions of individual amino acids in the peptide backbone. [ABSTRACT FROM AUTHOR]

In this paper, glucose and carbon nanotube (CNT) modified Li3V2(PO4)3 have been synthesised via a carbon thermal reduction method. The structure of Li3V2(PO4)3 has been confirmed by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning and transmission electron microscopy. The CNT modified Li3V2(PO4)3 materials, combined with the synthesized electrolyte, overcome the limitations of the low temperature performance of Li-ion batteries. The synthesized electrolyte is made up of 1.2 M LiPF6 dissolved in EC : DMC : EMC (1 : 1 : 1 in volume) with vinylene carbonate (VC) and propylene sulfite (PS) as the additive agents. The electrochemical behaviors of the cells have been evaluated by electrochemical tests over the temperature range from 25 to −20 °C. The specific capacities are 116.2, 108.2, 103.7, 96.3, and 86.1 mA h g−1 at 0.5C, 1C, 2C, 5C, and 10C, respectively, between 3.0 and 4.3 V at −20 °C. After 300 cycles, the capacity retention still reached 97% even at −20 °C. The excellent rate capability and low temperature performance are attributed to the synergistic effect between the CNTs and the synthesized low temperature electrolyte. [ABSTRACT FROM AUTHOR]

This paper presents an extraction method based on dispersive-nanoparticle-solid phase microextraction (DNSPME) for the preliminary preconcentration and subsequent spectrophotometric determination of trace amounts of malachite green (MG). The application of nanoparticles permits the easy separation and extraction of MG from trout fish water and natural water samples. The analyte was accumulated on a γ-Fe2O3 nanomaterial loaded on activated carbon (γ-Fe2O3-NPs–AC) that was identified by FESEM, XRD, FTIR, EDS and UV-Vis techniques. The influence of the expectable parameters on the extraction recovery, according to p ＜ 0.05, was investigated and judged using a two-level Plackett–Burman screening design with 7 variables (adsorbent mass, centrifugation time, eluent volume, ionic strength, pH, ultrasonication temperature and ultrasonication time). It was found that three significant variables namely adsorbent mass, eluent volume and pH have a great influence on optimization using a central composite design combined with a desirability function. The results showed that the semi-empirically obtained second-order model was able to efficiently predict the ER% for MG adequately with a coefficient of determination of 99.7% (p ＜ 0.001); the higher efficiency of the model was obtained through a good compromise between the experimental and predicted data. Working under the optimum conditions, specified as 0.6 mg of adsorbent and 120 μL of eluent volume at pH 6.0, led to the achievement of a high and reasonable linear range over 1–4000 ng mL−1 (R2 = 0.999) with a detection limit of 0.175 ng mL−1 and an obtained quantification limit of 0.583 ng mL−1. The relative standard deviation (RSD) for ten replicates was less than 3.50%. The proposed method was successfully applied for the determination of MG in trout fish water and natural water samples with excellent recoveries corresponding to spiked samples. All these results prove the suitability of the present method in terms of simplicity, easy operation conditions, efficiency and sensitivity for the determination of MG in real samples. [ABSTRACT FROM AUTHOR]

In this paper, we report two conjugated molecules 1 and 2 with four diketopyrrolopyrrole (DPP) moieties, which are linked by [2,2]paracyclophane. The energies of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of 1 and 2 were estimated from the respective onset oxidation and reduction potentials, which were determined on the basis of cyclic voltammetric data. Both 1 and 2 exhibit strong absorption in the visible region. Blended thin films of 1 and 2 with P3HT (poly(3-hexylthiophene)) in different weight ratios were utilized as active layers to fabricate solar cells. The results reveal that blended thin films of P3HT/1 and P3HT/2 at a weight ratio of 2 : 1 yielded the best photovoltaic performance with power conversion efficiencies (PCEs) up to 1.33% and 1.84% after thermal annealing. Blended thin films of P3HT/1 and P3HT/2 were characterized by XRD (X-ray diffraction) and AFM (atomic force microscopy) techniques. The low degree of inter-chain packing order and poor thin-film morphology are responsible for the relatively low PCEs. [ABSTRACT FROM AUTHOR]

This paper reports the synthesis of monoclinic bismuth vanadate (BiVO4) by the oxidant peroxide method with crystallization under hydrothermal conditions, and its catalytic performance on the photodegradation of pollutants under visible light. The as-synthesized BiVO4 materials were characterized by means of X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), Raman spectroscopy, Ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) and scanning electron microscopy (SEM). Hydrothermal treatment above 80 °C was required to obtain pure monoclinic BiVO4 phase by releasing V5+ ions from vanadium peroxo complexes. With the increase in hydrothermal reaction temperature, the particle size decreased. All BiVO4 samples presented large size and shape distribution and band gap of approximately 2.40 eV. The as-prepared BiVO4 catalysts showed high photoactivity for decomposition of model pollutants, methylene blue (MB) and rhodamine B (RhB) dyes, under exposure to visible light. The photodegradation mechanism was evaluated by adding scavengers, DMSO and KBrO3, which were used to probe ṖOH radical and conduction band (CB) electrons, respectively. It was observed that photodegradation of MB and RhB dyes is caused by the action of ṖOH radicals, and that BiVO4 CB electrons do not have reduction potential sufficiently high to reduce dissolved oxygen to O2−Ṗ. It was proven that the indirect mechanism, i.e.ṖOH radical formation, plays the major role on the BiVO4-assisted photodegradation process. [ABSTRACT FROM AUTHOR]

The present work is devoted to the characterization of gypsum synthesized on the laboratory scale by the atmospheric leaching of -60 mesh LD slag fines generated from a waste recycling plant (WRP) during the Linz–Donawitz process of steel making at the Tata Steel plant, Jamshedpur, India. The main objective of the present work was to synthesize and characterize gypsum which is a value added product from LD slag which is a waste product of the steel industry. The techniques used for the characterization were X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS) and thermogravimetry (TG) techniques. The XRD analysis revealed the presence of the anhydrite and gypsum phases in the product material as well as the presence of silica in the form of coesite. This observation was further correlated by the TG analysis which indicated that the synthetic gypsum was a mixture of gypsum (dihydrate), hemihydrate, soluble γ-anhydrite and insoluble β-anhydrite phases of gypsum. The morphology of the material was found to be like tabular crystals along with the presence of intermittent needle-like and rod like structures as observed from the SEM micrographs. The chemical composition was further confirmed by SEM-EDS analysis. The purity of the product was also estimated to be 86.12% calcium sulphate by the estimation of sulphur trioxide content. These findings have been discussed in detail in the subsequent sections of the paper. [ABSTRACT FROM AUTHOR]

This paper reports a novel one-pot biogenic synthesis of Au–SnO2 nanocomposite using electrochemically active biofilm. The synthesis, morphology and structure of the as-synthesized Au–SnO2 nanocomposite were in-depth studied and confirmed by UV-vis spectroscopy, photoluminescence spectroscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. It was observed that the SnO2 surface was decorated homogeneously with Au nanoparticles. The photoelectrochemical behavior of the Au–SnO2 nanocomposite was examined by cyclic voltammetry, differential pulse voltammetry, electrochemical impedance spectroscopy, and linear sweep voltammetry in the dark and under visible light irradiation. Visible light-induced photoelectrochemical studies confirmed that the Au–SnO2 nanocomposite had enhanced activities compared to the P–SnO2 nanoparticles. The Au–SnO2 nanocomposite was also tested for the visible light-induced photocatalytic degradation of Congo red and methylene blue, and showed approximately 10 and 6-fold higher photocatalytic degradation activity, respectively, compared to P–SnO2. These results showed that the Au–SnO2 nanocomposite exhibits excellent and higher visible light-induced photoelectrochemical and photocatalytic activities than the P–SnO2 nanoparticles, and can be used for a wide range of applications. [ABSTRACT FROM AUTHOR]

A composite cathode based on lanthanum chromate has uncovered tremendous potential for direct high temperature electrolysis. Unfortunately, a major setback of insufficient electrocatalytic activity limits the efficient carbon dioxide electrolysis. In this paper, catalytically active Ti is doped to partially replace Cr at the B-site in perovskite La0.75Sr0.25Cr0.5−xFe0.5TixO3−δ (LSCrFT, x = 0, 0.1, 0.2, 0.3, 0.4 and 0.5) to improve the polarization and electrocatalytic property of the cathode materials of the solid oxide electrolyzer. The transition of the dominant mechanism from p-type conduction to n-type conduction is observed for the LSCrFT cathode with the Ti doping level at x = 0.3. The doping of Ti in LSCrFT largely improves the electrode activity and therefore reduces electrode polarization resistance. A high-temperature CO2 electrolysis test demonstrates that the Faraday efficiencies of LSCrFT (x = 0.1) cathodes are enhanced by approximately 30% in contrast to bare LSCrF cathodes at 800 °C. [ABSTRACT FROM AUTHOR]

In this paper, an attractive organic complexation reaction reagent with lead ions was developed for lead extraction from cerussite. The leaching kinetics of cerussite was investigated using 5-sulfosalicylic acid solution as a lixiviant. The effects of several experimental parameters on the leaching of cerussite were investigated, and a kinetic model was developed to represent the relationship. The leaching process was controlled by a mixed kinetic model. The results showed that the leaching rate of cerussite increased with an increase in the stirring speed, temperature, and concentration, as well as a decrease in the particle size. The activation energy was found to be 37.07 kJ mol−1. The rate of reaction based on the mixed kinetic model-controlled process could be expressed as [1 − (1 −x)1/3]2 = [k0(SS)6.852(r0)−1.943(C)2.042 exp(−37.07/RT)]t. X-ray diffraction and scanning electron microscopy/energy-dispersive X-ray spectroscopy analyses indicated that a new solid reaction product may be formed. [ABSTRACT FROM AUTHOR]

Modification by metal-doping allows the design of new nanomaterials with enhanced optical properties. In this paper, the photocatalytic effects of Fe3+-doped W18O49 nanorods prepared by solution combustion synthesis were studied for the first time. The Fe3+-doped W18O49 powders were investigated by X-ray diffraction, high-resolution transmission electron microscopy, selected area electron diffraction, and X-ray photoelectron spectroscopy. The powders were well-crystalline with diameters ranging from 50 nm to 250 nm and the length decreasing from more than 10 μm to 4 μm on average. The photoluminescence (referred to as PL here after) spectrum showed that the emission intensity increased with increasing Fe3+ doping, suggesting that more defects were generated. Moreover, this novel composite catalyst displayed excellent photocatalytic efficiency towards the degradation of organic compounds in aqueous media under UV-visible light irradiation. In particular, 0.5 wt% Fe3+-doped W18O49 had the best photocatalytic efficiency. This improvement was mainly attributed to the synergistic effect between Fe3+ and W18O49 nanopowders and the defects in the nanostructure caused by doping. [ABSTRACT FROM AUTHOR]

This paper demonstrates a novel and green approach for the synthesis of Fe3O4 nanoparticles using the leaf extract of Artemisia annua (A. annua), which is widely distributed in Asia as a medicinal plant. The formation of Fe3O4 nanoparticles was observed by UV-Vis spectroscopy. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDAX), Fourier transform infrared (FT-IR) spectroscopy, vibrating sample magnetometry (VSM), and thermogravimetric analysis (TGA). TEM analysis of Fe3O4 nanoparticles showed that they were spherical in shape with an average size of 6 nm. The synthesized Fe3O4 nanoparticles were used as a catalyst for the preparation of biologically interesting benzoxazinone and benzthioxazinone derivatives in high yields. These results showed that the synthesized Fe3O4 nanoparticles could be used as a catalyst in organic synthesis. [ABSTRACT FROM AUTHOR]

In this paper, a high-surface-area mesoporous sulfated nano-titania exposed with (101) facets was prepared by a simple hydrothermal method without any template followed by surface sulfate modification. The physicochemical properties of the as-prepared catalyst were well characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), Raman spectroscopy (Raman), Fourier transform infrared spectroscopy (FTIR), N2 adsorption–desorption isotherms, temperature programmed desorption of NH3 (NH3-TPD), X-ray photoelectron spectroscopy (XPS) and pyridine adsorption infrared spectroscopy. The BET surface area of sulfated nano-titania with exposed (101) facets was 121 m2 g−1. Well dispersed bidentate sulfate groups were linked to the exposed (101) facets of anatase nano-titania. Acid sites with moderate- and superacidic strength formed in the sulfated titania catalyst. Also, the as-prepared sulfated sample possessed both Lewis and Brønsted acid sites. The catalytic activity of sulfated nano-titania with exposed (101) facets was evaluated using the esterification reaction between acetic acid and n-butanol. It was found that the yield of butyl acetate increased to about 92.2% in the presence of the catalyst. Compared with the exposed (001) facets, the exposed (101) facets showed better catalytic activity of sulfated TiO2 in esterification. The effects of different reaction conditions were discussed in detail. Additionally, the as-prepared sulfated sample could be efficiently recycled and regenerated by simple soaking in sulfuric acid followed by calcination. [ABSTRACT FROM AUTHOR]