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Copper (Cu) provides a cost-effective means of producing value-added fuels through the electrochemical reduction of carbon dioxide (CO2RR). However, we observed the production of hydrocarbons via CO2RR on commercial Cu films is less efficient because of the surface impurities, i.e., Fe. Carbon monoxide (CO), a reaction intermediate of CO2RR to hydrocarbons, binds strongly to the Fe sites and interrupts the production of hydrocarbons, resulting in an active hydrogen evolution reaction (HER). Herein, we report a method of blocking the effect of Fe impurities on the Cu surface through the preferential growth of nano-sized metal-organic frameworks (MOFs) on Fe site. When zirconium (Zr)-based MOFs (UiO-66) forms a compensating layer on Cu film via the terephthalic acid (TPA)-Fe coordination bond, the UiO-66 coated Cu film (UiO-66@Cu) presents significantly improved hydrocarbon Faradaic efficiency (FE) of 37.59% compared to 14.68% FE on commercial Cu film (99.9% purity) by suppressing HER. According to X-ray photoelectron spectroscopy (XPS) analysis, the UiO-66 ligand binds to entire metallic Fe site on the Cu surface, while metallic Cu is retained. Thus, UiO-66@Cu provides active sites of Cu for CO2RR and leads to highly efficient and selective production of hydrocarbons.

Excess fluoride in water poses a threat to ecology and human health, which has attracted global attention. In this study, a series of lanthanum-based metal–organic frameworks (La-MOFs) were synthesized by varying the organic ligands (i.e., terephthalic acid (BDC), trimesic acid (BTC), biphenyl-4,4-dicarboxylic acid (BPDC), 2,5-dihydroxyterephthalic acid (BHTA), and 1,2,4,5-benzenetetracarboxylic acid (PMA)) to control the microscopic structure of the MOFs and subsequently apply them for the removal of fluoride in water. The maximum capture capacities of La-BTC, La-BPDC, La-BHTA, La-PMA, and La-BDC at 298 K are 105.2, 125.9, 145.5, 158.9, and 171.7 mg g−1, respectively. The adsorption capacity is greater than most reported adsorbents. The adsorption isotherms of La-MOFs for fluoride are well fit to the Langmuir isotherm model. In addition, the adsorption kinetics of La-BTC, La-BPDC, La-BHTA, La-PMA, and La-BDC follows the pseudo-second-order kinetic model, and the kinetic rate-limiting step of adsorption is chemical adsorption. Thermodynamics revealed that temperature is favorable for the adsorption of fluoride. Meanwhile, La-BTC, La-BPDC, La-BHTA, La-PMA, and La-BDC are suitable for the removal of fluoride in a relatively wide pH range (4.0–9.0). Simultaneously, from X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) analysis, electrostatic attraction and ligand exchange are identified as the main action mechanisms for the adsorption of fluoride of La-MOFs. The prepared La-MOFs are used as efficient adsorbents for removal of fluoride in actual water, indicating that they have great potential in removing fluoride in real and complex environmental water. This work provides a new strategy for designing adsorbents with adjustable microstructure and expected function to effectively recover fluorosis in water.

Poly-p-phenylene terephthamide (PPTA) is widely applied in bulletproof products and composite materials because of its high strength, high modulus, high temperature resistance and creep resistance. The PPTA molecule with highly symmetrical and regular structure is linear structure formed by the alternating connection of benzene ring and amide bond, and the amide bonds between the molecular chains form strong hydrogen bonds. Therefore, the dissolution and depolymerization of PPTA is very challenging. In this work, an efficient catalytic system was developed for the controllable degradation of waste PPTA, and the high-value added monomers terephthalic acid (TPA) and p-phenylenediamine (PPD) were recovered. The results show that the amide bonds of PPTA can be selectively cleaved by the strong Bronsted base catalysts in alcohols, especially in the NaOH/n-butanol system. Under the optimal degradation conditions (5 wt% NaOH in n-butanol, 180 °C, 6 h), the percentage degradation of PPTA is 100%, and the yields of TPA and PPD are 92.0% and 91.5%, respectively. In addition, it is found that the wettability of n-alcohols on PPTA monofilament and the addition of a small amount of water have important influences on the degradation of PPTA. The work elucidates the degradation mechanism of PPTA, and reveals the important factors affecting the depolymerization of PPTA.

Lignin is the only renewable aromatic material in nature and contains a large number of oxygen-containing functional groups. High-value and green utilization of "lignin-to-chemicals" can be realized via using lignin to produce fine chemicals such as phenols and carboxylic acids, which can not only reduce the waste of lignin in the process of lignocellulosic biomass treatment, but gradually make the substitution of traditional fossil fuels come true. The hydrogenolysis process under catalysis of metal catalyst has high product selectivity and less impurity, which is suitable for the production of same type or single fine chemicals. Hydrogenolysis of lignin via metal catalysts to produce lignin oil, and further modification of functional groups (e.g. methoxyl, alkyl and hydroxyl group) of depolymerized monomers in the bio-oil to yeild phenols and terephthalic acid are reviewed, and catalytic mechanisms are briefly summarized in this paper. Finally, the problems of lignin catalytic conversion existing currently are investigated, and the future development of this field is also prospected.

The design of efficient nanostructured catalysts is highly desirable for promoting the hydrogenation of 4-carboxybenzaldehyde (4-CBA), which are the key process of hydrorefining of crude terephthalic acid (CTA) to pure terephthalic acid (PTA). Herein, the Pt-FeNi@C, Pt-Fe@C and Pt-Ni@C catalysts were developed and proved to be active for the selective hydrogenation of 4-CBA. As a result, the excellent 4-hydroxymethylbenzoic acid (4-HMBA) selectivity (85%) and benzoic acid (BA) selectivity (88%) were achieved on Pt-FeNi@C and Pt/C, respectively. In comparison with the commercial Pd/C catalyst, the Pt-FeNi@C catalyst exhibits excellent activity (97%) and reduces the occurrence of decarbonylation. Moreover, the Pt-FeNi@C catalyst exhibits excellent recyclability: the catalytic activity did not decrease significantly after four reaction cycles. In combination with detailed characterization, the Pt-FeNi@C catalyst has porous graphene core-shell architecture and remarkable electron transfer capacity. This work may provide some inspirations for the exploration of new PTA hydrofining catalysts.

This paper reports that the optical properties of anthraquinone (AQ) and its photo-catalytic performance in the visible light-driven p-xylene (PX) oxidation can be fine-tuned and improved through varying its skeleton substituents at the molecular level, and the electron-withdrawing substituent exhibits a better improvement effect than the electron-donating one. The best catalyst 2-carboxyanthraquinone (AQ-COOH) can achieve 70.9% PX conversion and 88.2% p-toluic acid selectivity under visible light illumination and 1 atm O2 pressure. The addition of benzenesulfonic acid in the above photocatalytic system can further increase PX conversion to 86.7%, along with a significant improvement in the selectivity of p-carboxybenzaldehyde and terephthalic acid, which likely originates from the unique recombination behavior of the photo-generated charge carriers of the catalyst and the additive driven by the strong interactions between their aromatic skeletons and acidic substituents. Furthermore, AQ-COOH can achieve almost quantitative yield of acetylacetone in ethylbenzene photooxidation and the regulating effect of toluene's para-position substituents on its reactivity is also reported in the AQ-COOH photocatalysis system. Based on quenching tests and EPR spectral characterizations, the oxygen vacancies (h+), superoxide free radicals (O2•-) and singlet oxygen (1O2) as the photo-generated active species are involved in the proposed photo-catalysis mechanism.

In recent years, poly (butylene adipate-co-terephthalate) (PBAT) has been widely used. However, PBAT-degrading bacteria have rarely been reported. PBAT-degrading bacteria were isolated from farmland soil and identified. The effects of growth factors on the degradation of PBAT and the lipase activity of PBAT-degrading bacteria were assessed. The degradation mechanism was analyzed using scanning electron microscopy, attenuated total reflection Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, X-ray diffraction, and liquid chromatography-mass spectrometry. The results showed that Stenotrophomonas sp. YCJ1 had a significant degrading effect on PBAT. Under certain conditions, the strain could secrete 10.53 U/mL of lipase activity and degrade 10.14 wt.% of PBAT films. The strain secreted lipase to catalyze the degradation of the ester bonds in PBAT, resulting in the production of degradation products such as terephthalic acid, 1,4-butanediol, and adipic acid. Furthermore, the degradation products could participate in the metabolism of YCJ1 as carbon sources to facilitate complete degradation of PBAT, indicating that the strain has potential value for the bioremediation of PBAT in the environment.

Poly(ethylene terephthalate) hydrolase (PETase) from Ideonella sakaiensis 201-F6 was expressed and purified from Escherichia coli to hydrolyze poly(ethylene terephthalate) (PET) fibers waste for its monomers recycling. Hydrolysis carried out at pH 8 and 30 °C was found to be the optimal condition based on measured monomer mono(2-hydroxyethyl) terephthalate (MHET) and terephthalic acid (TPA) concentrations after 24 h reaction. The intermediate product bis(2-hydroxyethyl) terephthalate (BHET) was a good substrate for PETase because BHET released from PET hydrolysis was efficiently converted into MHET. Only a trace amount of MHET could be further hydrolyzed to TPA. Class I hydrophobins RolA from Aspergillus oryzae and HGFI from Grifola frondosa were expressed and purified from E. coli to pretreat PET surface for accelerating PETase hydrolysis against PET. The weight loss of hydrolyzed PET increased from approximately 18% to 34% after hydrophobins pretreatment. The releases of TPA and MHET from HGFI-pretreated PET were enhanced 48% and 62%, respectively. The selectivity (TPA/MHET ratio) of the hydrolysis reaction was approximately 0.5.

Sequential biocatalytic process based on lipase catalysis has been developed for the decomposition of bis(2-hydroxyethyl)terephthalate (BHET) as model molecule for polyterephthalic ester (PET) recycling. The sequential process comprised lipase enzyme: (i) hydrolysis of BHET and (ii) esterification of the resulted products (mono(2-hydroxyethyl)terephthalic acid, MHET and terephthalic acid, TPA) using dimethyl carbonate (DMC). Screening of lipases for the BHET hydrolysis revealed Aspergillus niger lipase as a valuable biocatalyst. Further, the sequential biocatalytic process had been evaluated for different concentrations of lipase and DMC. 2% (v/v) DMC afforded an advanced biocatalytic conversion of BHET providing maximum 53 % TPA and 44 % mono-methyl terephthalic acid (MTP1) in the products mixture. Aromatic alcohols as o-cresol, thymol or carvacrol proved also the ability to degrade BHET to TPA and corresponding TPA esters based on sequential biocatalysis.

Biomass conversion to value-added chemicals has received tremendous attention for solving global warming issues and fossil fuel depletion. 5-Hydroxymethylfurfural (HMF) is a key bio-based platform molecule to produce many useful organic chemicals by oxidation, hydrogenation, polymerization, and ring-opening reactions. Among all derivatives, the oxidation product 2,5-furandicarboxylic acid (FDCA) is a promising alternative to petroleum-based terephthalic acid for the synthesis of biodegradable plastics. This review analytically discusses the recent progress in the thermocatalytic, electrocatalytic, and photocatalytic oxidation of HMF into FDCA, including catalyst screening, synthesis processes, and reaction mechanism. Rapid fundamental advances may be possible in non-precious metal and metal-free catalysts that are highly efficient under the base-free conditions, and external field-assisted processes like electrochemical or photoelectrochemical cells.

In this study, the flexible nanoporous MIL-53(Fe) (MIL = Materials of Institute Lavoisier) was used as an efficient support for in-situ and covalent binding immobilization of Humicola insolens lipase (HIL) and Rhizomucour miehei lipase (RML). In the covalent attachment procedure, the support synthesized under ultrasound irradiation was functionalized by N,N-dicyclohexylcarbodiimide and then attached to the enzyme. In the case of in-situ immobilization method, the support was easily synthesized in water and at room temperature by just replacing terephthalic acid with disodium terephthalate. The in-situ approach was very efficient in terms of enzyme loading, resulting in the immobilization of 66 mg and 81 mg· g−1 of RML and HIL, respectively, While in the covalent attachment about 15 mg· g−1 of enzymes were immobilized. Moreover, pH, thermal stability, and reusability of the prepared biocatalysts were investigated. The in-situ immobilization of H. insolens considerably improved its stability compared with covalent attachment even in extreme conditions of temperature (around 100 % of its initial activity at 80 °C) and pH (over 90 % at pH 5 and about 100 % at pH 9) and also allowed the enzyme to be reused up to 7 reaction cycles with more than 90 % residual activity.

MIL-53 is a metal organic framework (MOF) belonging to the MIL (Material Institute Lavoisier) group. It is a 3-D framework, built up by the combination of metal salt (Al, Fe, Cr) and linker (terephthalic acid). It is well known for its flexibility in structure and the phenomenon of breathing. It was first synthesized in the year 2002 by Gerard Ferey using chromium salt and widely used for adsorption/separation applications due to its remarkable flexibility and porous structure. In the formation of MIL-53, different ranges of metal ions and linker are used which provides the possibility of the formation of different compositional variety. From the literatures reported in this paper, it was found that the researchers have used just three synthesis routes solvothermal, electrochemical, and microwave-assisted methods for the synthesis of MIL-53 and found to have only few applications. This paper aims to appraise the methods being used for synthesis of MIL-53 and its several applications.

Hydrothermal degradation was used to pretreat terylene with an aim of noticeably improving the yield of fermentable monomers: terephthalic acid (TPA), mono (2- hydroxyethyl) terephthalic acid (MHET), bis-hydroxyethyl terephthalate (BHET), and ethylene glycol (EG). After 0.5 h of reaction time at 180 °C, hydrothermal degradation with ammonia led to almost complete conversion of the terylene to TPA, MHET, BHET and EG, which were then transformed by Taonella mepensis WT-6 to bacterial cellulose (BC). Furthermore, the optimum fermentation conditions with the maximum BC yield were 5.0 g/L yeast extract, 30.0 °C, pH 9.0, 8.0% inoculum, and hydrolysate TOC (5.02 g/L). Additionally, mechanical and thermal analysis revealed that the properties of BC produced from TAH medium were similar to those of BC produced with HS medium. Considering the substantial amount of global terylene waste being produced, this study provides an alternative solution for the biosynthesis of BC.

Mesoporous KIT-5 was functionalized with g-C3N4 nanoparticles using trichloroacetic acid and terephthalic acid as acid modulators under hydrothermal conditions. The surface morphology, elemental composition, stability, surface area, pore size and pore volume of the functionalized KIT-5-g-C3N4 nanomaterial were determined using SEM, EDAX, Zeta potential analysis and BET surface area analysis respectively. The functionalized mesoporous KIT-5 material was screened for cationic dye degradation. The material was found to decolorize and degrade the cationic dye methylene blue completely under visible light conditions. The adsorption and degradation of the dye by functionalized KIT-5-g-C3N4 nanomaterial were studied using UV spectrophotometer. The photo degradation efficiency of the functionalized KIT-5-g-C3N4 nanomaterial was found to be 85.5%. The recyclability and reusability of the functionalized KIT-5-g-C3N4 nanomaterial in dye degradation was studied. The mechanism for the successful dye degradation by functionalized KIT-5-g-C3N4 nanomaterial was also discussed based on electro static interaction.

The effects of concentration and an oriented external electric field on the transformations of hydrogen-bonded structures of trimesic acid (TMA) and terephthalic acid (TPA) have been investigated at a liquid–solid interface by scanning tunneling microscopy (STM). The triangular periodic TMA framework can be transformed into a flower-like structure by changing the STM sample bias sign in situ. Networks of TMA and TPA are porous at a negative substrate bias, but typically change to relatively compact forms when the polarity of the applied bias is reversed. This change is reversible if the applied bias is reversed. The effects have potentials to locally control the capture and release of analytes in host-guest systems and the 2D morphology in multicomponent layers.

Control of product quality plays a crucial role in petrochemical industries. In this paper, we propose a new strategy to control the quality of purified terephthalic acid (PTA) product. In this approach, the PTA quality is controlled by monitoring the concentration of the main impurity in the hydropurification process, which is 4-carboxybenzaldehyde (4-CBA) in the crude terephthalic acid (CTA) powder. To attain the research objectives, a dynamic dispersion model is developed in the face of catalyst deactivation, considering the vital operating parameters. The CTA powder streams with low and high 4-CBA concentrations can be effectively used through a proper (and controlled) mixing procedure. This strategy can be applied by controlling the ratio of the mass flowrates of the two streams, having high and low concentrations. The positive effect of H2 partial pressure on the system performance can be implemented by a small decrease in reactor temperature. Off-spec PTA powder can be used with the CTA powder having a high 4-CBA concentration. Increasing temperature accelerates the reduction rate of the Pd/C catalyst surface area, leading to an unfavorable sintering phenomenon. The decreased activity of Pd/C catalyst is in good agreement with the normalized ratio of decrease in the surface area of pure Pd with increasing temperature.

The design of satisfied catalytic activity and stable catalysts for the oxygen evolution reaction (OER) is crucial in the production of hydrogen in electrolyzed water. Herein, S-doping NiCo-metal organic framework (NiCoS-MOF) were prepared successfully in situ on a nickel foamed (NF) substrate by used terephthalic acid (TPA) as an organic ligand via the original one-step solvothermal process, NiCoS-MOF reveals the electrocatalytic performance by the low overpotential of 71 mV at 10 mA cm−2 and the tafel slope of 74.4 mV dec−1 under alkaline condition (1 M KOH) served as OER electrodes directly. The i-t curve for 48 h at 1.50 and 2.14 V (vs.REH) showed excellent stability of NiCoS-MOF and the structure had no significant collapse after 1000 cycles. Superior OER activity and excellent stability could ascribed to the fluffy and orderly petal-like structure, which exhibited dispersal of the active sites and facilitated the evolution of oxygen during the catalysis process. The work enriched exploration of heteroatom-doped bimetallic MOFs in energy storage and conversion.

Metal organic frameworks (MOFs) are considered as very promising positive electrode materials for supercapacitors. To achieve good electrochemical performance, in this work, we report a mixed-ligand approach to prepare modified Ni-MOF by using trimesic acid (BTC) as the modulator to partially replace the terephthalic acid (PTA) ligands. The introduction of BTC can induce the formation of nanosheets with inserted albizia flower-like spheres, where the nanowires on the albizia flower-like spheres can provide rich redox reaction sites and the “spacer” spheres between the layers can hinder the aggregation of the 2D nanosheets to provide fast transport pathways. Moreover, adsorption simulation shows that the adsorption energy of OH− on the mixed organic ligands is increased after introducing the BTC ligands, which may improve the reversible redox reaction kinetics in the electrode materials. The as-obtained albizia flower-like spheres@nanosheets structured Ni-MOF with the optimized amount of BTC exhibits a high capacitance of 920 F g−1 at 1 A g−1, good rate capability of 61% at 20 A g−1, and an excellent cycling stability in 6 M KOH electrolyte. This work may provide helpful guidance for controlling the structure and surface property of MOFs to improve the electrochemical performance for supercapacitors.

In this work, a holmium oxide (Ho2O3/CNT) photocatalysts were successfully synthesized through a MOF assisted route for the first time. The effects of the morphology and purity on the photocatalytic behavior of the products, were investigated by determining various physicochemical properties. The Ho2O3/CNT nanocomposite was systematically analyzed by powder X-ray diffraction (P-XRD), transmission electron microscopy (TEM), ultraviolet–visible diffuse reflectance spectroscopy (UV–vis DRS), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy studies. The Ho2O3 derived from a MOF assisted synthetic route using Ho(NO3)3·5H2O and terephthalic acid with a 1:1 M ratio at a temperature of 750 °C for 3 h prove the most advantageous, 98% degradation of 20 mg/L aqueous tetracycline pollutant was observed within 60 min. The elevated photocatalytic activity was mainly attributable to the unique synthetic route, improved crystallinity, wide UV-light absorption rate and excellent adsorption capabilities of CNT, as well as enhanced oxygen deficiency. The photocatalytic results confirm that the Ho2O3/CNT nanocomposite is an efficient photocatalyst for the degradation of toxic tetracycline pollutant and is thus suitable for use in environmental remediation.

The development of technologies for poly(ethylene terephthalate) (PET) depolymerization, such as biocatalysis, has been pointed as a very promising alternative to chemical hydrolysis processes. This work aims to understand the behavior of Yarrowia lipolytica, a robust yeast for diverse applications, in the presence of molecules from the PET production chain such as monoethylene glycol (MEG), terephthalic acid (TPA), bis (2-hydroxyethyl) terephthalate (BHET), PET oligomers, amorphous PET and post-consumer PET. The yeast was cultivated in rich media with and without glucose addition, in order to compare monomers release or consumption. TPA and MEG were consumed more intensely in the absence of glucose. The addition of the diester BHET yielded a 3-fold increased lipase production both at 160 rpm (118 U/L) and 250 rpm (385 U/L). In addition, 250 rpm agitation also provided a higher consumption of TPA (26% increase). The mono(2-hydroxyethyl) terephthalate (MHET) was the main intermediate released during polymer hydrolysis, followed by TPA and BHET. Thus, the use of Yarrowia lipolytica, which is capable of catalyzing the PET hydrolysis is of great potential to reduce the environmental impacts caused by unappropriated disposal of packages.

The Diels-Alder reaction of biomass-derived dimethyl 2,5-furandicarboxylate (DMFDC) with ethylene followed by dehydrative aromatization is a sustainable route for the production of terephthalic acid, a monomer used for the synthesis of polyethylene terephthalate (PET). In this work, a series of heteropolyacid (HPA) catalysts with different supports, in this case SiO2, TiO2 and ZrO2, and hetero-addenda atoms, here phosphotungstic acid (HPW), silicotungstic acid (HSiW) and phosphomolybdic acid (HPMo), were used as catalysts, and their structure-activity correlation in the conversion of DMFDC to terephthalate was examined based on the density and strength of the acid sites. Characterization by XRD and Raman indicated that the Keggin structures of HPAs were well preserved on the SiO2 support compared to other supports, resulting in strong Bronsted acidity. The silica-supported HPW and HSiW catalysts exhibited significantly higher activity for terephthalate production than other supports and HPMo catalysts, but their activity were not correlated with the total acidity as measured by NH3-TPD. In contrast, the catalyst acid strength, as determined by the NH3 desorption temperature, decreased in the order HPW/SiO2 > HSiW/SiO2 >> HPW/ZrO2 > HPW/TiO2 > HPMo/SiO2 and was well correlated with the turnover rate for terephthalate production, suggesting that the higher activity of HPW/SiO2 is at least partly due to its stronger Bronsted acidity and that promoting the dehydration step of this reaction is a key to improving the selectivity to terephthalate. The effects of reaction conditions, in this case the acid loading amount, solvent used, temperature, and time, were also investigated with the most active silica-supported HPW catalysts to optimize the terephthalate yield. The 25%-HPW/SiO2 catalyst demonstrated a remarkable terephthalate yield of ∼60% with almost complete conversion under the optimum condition.

Mixed-ligand metal–organic frameworks (MIXMOFs) containing two or more organic linkers that exhibit functionalities can show improved selective gas adsorption and separation properties with respect to those of the conventional MOFs. In this study, the mixed-ligand UiO–66(Zr) framework was rapidly prepared by employing a microwave-assisted continuous-flow method, which can be easily scaled up for efficient mass production. A microfluidic syringe pump system was used to introduce the precursor solutions of zirconium metal salt and ligand mixture (terephthalic acid and 2-amino terephthalic acid) into a polytetrafluoroethylene tubular reactor kept under microwave irradiation. MIXMOFs were obtained within 10 min, a much shorter time than the reaction time required by the conventional heating method. The prepared samples were characterized by N2 porosimetry, field-emission scanning electron microscopy, Fourier transform infrared spectrometry, thermogravimetric, and powder X-ray diffraction analyses to elucidate the effects of the ligand ratios. Furthermore, the toluene adsorption–desorption tests were conducted using the synthesized mixed-ligand UiO–66(Zr) adsorbents at different temperatures.

In this work, hexacyanoferrate intercalated Ni/Al LDH (Ni/Al–Fe(CN)6 LDH) nanozyme was synthesized by one-pot co-precipitation method and used for determination of chromium in water samples by employing its peroxidase mimicking activity. The synthesized nanozyme can effectively catalyze the oxidation of fluorometric peroxidase substrate terephthalic acid by H2O2 to produce a highly fluorescent product. It was found that Cr(VI) promotes the peroxidase-like activity of Ni/Al–Fe(CN)6 LDH and this effect was intensified by increasing the Cr(VI) concentration. Several variables affecting the fluorescence intensity including the concentration of nanoparticles and reagents as well as reaction time were investigated and optimized. Under the optimal conditions, good linearity was observed in the range of 0.067–10 μM Cr(VI), and limit of detection and quantification were found to be 0.039 and 0.131 μM, respectively. Furthermore, the developed method showed good applicability for the determination of total Cr based on the oxidation of Cr (III) to Cr (VI). The applicability of the proposed method was demonstrated by analyzing various environmental water samples. The presented nanozyme displayed superior benefits in terms of reusability, repeatability, cost and environment-friendly features. The present work aims to expand LDHs based enzyme mimics to optical sensor fields.

Mesoporous polymeric metal-organic frameworks (mesoporous polymeric MOFs) are prepared on fluorine-doped tin oxide (FTO) substrate using hydrophilic terephthalic acid as the ligands, titanium isopropoxide as polymeric MOF precursors, and amphiphilic graft copolymers (i.e., poly(vinyl chloride)-graft-poly(oxyethylene methacrylate) (PVC-g-POEM) as structure-directing agents. The hydrophilic POEM chains in amphiphilic graft copolymers interact with the hydrophilic ligands and polymeric MOF precursors. Following thermal treatment at 500 °C, mesoporous polymeric MOFs are transformed to mesoporous TiO2 with high specific surface area and crystallinity, suitable for photovoltaic and photocatalytic applications. Solid-state dye-sensitized solar cells (ssDSSCs) and dye-sensitized solar cells (DSSCs) fabricated with mesoporous TiO2 photoanodes have efficiencies of 7.45 and 8.43 % at 100 mW/cm2, which is much higher than that of ssDSSCs and DSSCs with photoanodes of conventional TiO2 (5.36 and 7.14 %), respectively. The enhanced efficiency is attributed to good interconnectivity, larger surface area, and high porosity of the mesoporous TiO2, which results in suppressed interfacial charge recombination loss, enhanced electron transport, increased dye loading, and facilitated penetration of the electrolytes. Mesoporous TiO2 shows excellent activity as a photocatalyst for the degradation of humic acid under UV light irradiation.

p-Toluic acid is a major content of terephthalic acid wastewater and is a cause of secondary water pollution. p-Toluic acid in aqueous solution was degraded by using photo-fenton, photo-peroxidation, photo-oxidation and peroxidation processes. A low-pressure mercury vapour lamp was taken in combination with different oxidants to degrade p- toluic acid in this study. Substrate concentration was fixed by utilizing a UV–Visible spectrophotometer. The results indicated that photo-fenton process achieved degradation rate due to synergistic effect between UV and Fe2+/H2O2. The degradation rate follow the sequence: photofenton (UV/ Fe2+/H2O2) > photo-peroxidation (UV/H2O2) > photo-oxidation (UV) > peroxidation (H2O2). The photodegradation processes were adhered to first order dynamics.

Directly oxidative esterification of Biomass-derived 5-hydroxymethylfurfural (HMF) into dimethyl furan dicarboxylate (DMFDCA) is a promising route for the replacement of petroleum-derived commodity chemical terephthalic acid (TPA) extensively employed in polyester synthesis. Co-based N-doped carbon materials are one of the most promising applied catalysts for oxidative esterification reaction, however, the active sites and reaction pathway of these catalysts have not been clearly clarified, which is crucial to the practical application. Herein, we report that ZIF-67 (a zeolitic imidazolate framework (ZIF)-type cobalt-containing MOF) derived Co@C-N material is a highly effective catalyst for the selective conversion of HMF into DMFDCA in 95% yield. The high activity of the ZIF-67 derived nanocarbon composites Co@C-N can be attributed to the electron transfer between nitrogen-doped carbon shells and Co nanoparticles. The appropriate graphitic N and pyridinic N doping increases the electronic mobility and active sites. Density functional theory (DFT) simulations indicated that oxygen, HMF and methanol molecules are adsorbed and activated on C-N materials. Furthermore, no 2, 5-diformylfuran (DFF) was captured as an intermediate because the oxidative esterification of aldehyde preferentially occurred than the oxidation of hydroxyl group in HMF. We anticipate that these results can drive progress in the bio-based polymers sector and oxidative esterification reaction.

A significantly growing interest is to design new biodegradable polymers in order to solve fossil resources and environmental pollution problems associated with conventional plastics. A kind of new biodegradable polymers, aliphatic–aromatic co-polyesters have been researched widely and developed rapidly in recent years, since that can combine excellent biodegradability provided from aliphatic polyesters and good properties from aromatic polyesters. Out of which, poly (butylene-adipate-co-terephthalate) (PBAT) shows the most importance. PBAT has been commercialized by polycondensation reaction of butanediol (BDO), adipic acid (AA) and terephthalic acid (PTA) using general polyester manufacturing technology. And it has been considered to have desirable properties and competitive costs to be applied in many fields. Therefore, this review aims to present an overview on the synthesis, properties and applications of PBAT. Keywords: Biodegradation, Polyester, PBAT, Synthesis, Property, Application

Zirconium metal–organic frameworks ZrOBDC (where BDC = C6H4(COOH)2, terephthalic acid) doped and co-doped with rare earth ions Ln (ZrOBDC:Ln3+, where Ln3+ = Eu3+ and Tb3+ as well as Er3+ and Yb3+) were used as precursors for the design of tetragonal rare earth doped zirconia nanoparticles (t-ZrO2:Ln3+ NPs) through annealing process. Preparation, characterization and luminescence properties of ZrOBDC:Ln3+ and ZrO2:Ln3+ NPs were investigated. The as-obtained t-ZrO2:Ln3+ NPs have high purity with an average size of 20–30 nm. The luminescence spectra of ZrOBDC:Tb3+ and ZrOBDC:Eu3+ display strong green and red emission at around 544 and 611 nm which correspond to 5D4 → 7F5 and 5D0 → 7F2 transitions of Tb3+ and Eu3+ ions, respectively. The green and red up-conversion emissions of ZrO2:Er3+,Yb3+ NPs due to 2H11/2, 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2 transitions of the Er3+ ions are observed under 976 nm laser excitation.

Two new Ni(II) coordination polymers (CPs) [Ni(TP)(L1)(H2O)]n (1) and [Ni(TP)(L2)]n (2), were synthesized via hydrothermal reaction (H2TP = terephthalic acid, L1 = 1,6-bis(2-methylbenzimidazol-1-yl)hexane, L2 = 1,6-bis(5,6-dimethylbenzimidazol-1-yl)hexane, and structurally characterized by X-ray single crystal diffraction analysis, elemental analyses, thermogravimetric analysis, X-ray powder diffraction and IR spectra. CP 1 exhibits a 2D hcb layer, which is further extended into 3D supramolecular architecture by classical O–H⋯O hydrogen-bonding interactions. CP 2 possesses a 3D 4-connected sra framework. Both CPs possess high thermal stability and promising photocatalytic activities for the degradation of methylene blue (MB) under UV irradiation. The photocatalytic mechanism was investigated by introducing benzoquinone (BQ), the ammonium oxalate (AO), and tert-butyl alcohol (TBA) as superoxide radical (·O2−), hole (h+), and hydroxyl radical (·OH) scavengers, respectively.

2,5-Furandicarboxylic acid (FDCA) has the potential to replace terephthalic acid (TPA) as a building block in the preparation of bio-based and degradable polyester materials. However, the lack of efficient and stable catalysts limits the commercial viability of FDCA production. In this work, metalloporphyrins were immobilized on mesoporous SiO2 and used as a novel oxidase to convert 5-hydroxymethylfurfural (HMF) to FDCA. As the catalytic active center of P450 monooxygenases and horseradish peroxidase, supported palladium, manganese, ferri, and cobalt porphyrins via ionic-liquid-functionalized SiO2 (PdPOP-SiO2, MgPOP-SiO2, FePOP-SiO2 and CoPOP-SiO2) were able to simulate oxidase alone under mild conditions. 100% HMF (0.02 M) conversion and 94.94% FDCA yield were achieved using PdPOP-SiO2 as a biomimetic oxidase after a 12 h reaction at 373 K in water at atmospheric pressure. This type of mimetic oxidase is stable, inexpensive, and readily available, and the method developed in this work can potentially be used to oxidize HMF to FDCA in an industrial setting.

A novel heterostructured MgFe 2 O 4 /Bi 2 MoO 6 composites were rationally designed and successfully synthesized firstly by a successive hydrothermal process and in-situ ball-milling followed by high temperature calcination technology. The investigation showed that the MgFe 2 O 4 nanoparticles were closely anchored on the surface and edge of Bi 2 MoO 6 nanoplates. Under visible-light illumination, the 20 wt% MgFe 2 O 4 /Bi 2 MoO 6 samples showed the highest photocatalytic activity for the degradation of Malachite Green (MG) with 120 min and had the maximum of reaction rate constant (0.0113 min −1 ), which was approximately 8.07 times than that of pure Bi 2 MoO 6 (0.0014 min −1 ). Moreover, the effects of MG concentration, coexisting ions, and water sources for photocatalytic activity were also investigated. The detection of reactive species demonstrated that the ∙O 2 – and h + were playing important roles during MG removal process. Besides, the Z -scheme transfer mechanism of photoexcited electron-hole over composite were proved by using nitrotetrazolium blue chloride (NBT, ∙O 2 – trapping agent) and terephthalic acid (TA, ∙OH trapping agent) trapping methods. The significant improvement of photocatalytic performance can be predominantly interpreted as enhancing light harvesting ability, increasing charge carriers density as well as the formation of Z -scheme system between Bi 2 MoO 6 and MgFe 2 O 4 semiconductor.

During tribocorrosion of biomedical alloys, potentials may shift cathodically across the metal-oxide-electrolyte interface resulting in the increased reduction of local oxygen and water molecules. The products of reduction are thought to include reactive oxygen species (ROS) as well as hydroxide ions. Using fluorescent probes, developed for labeling intracellular ROS-based hydroxyl radicals (OH·) and hydrogen peroxide (H2O2), ROS generation due to reduction reactions at cathodically biased CoCrMo alloy surfaces was measured directly. Using terephthalic acid (TA) and pentafluorosulfonylbenzene-fluorescein (PFF) as fluorescent dosimeters, it was found that OH· and H2O2 concentrations increased up to 16 h and 2 h, respectively. Decreases in fluorescence past these time points were attributed to the continuous onset of reduction reactions consuming both the ROS and/or dosimeter. It was also found that voltages below and including −600 mV (vs. Ag/AgCl) produced measurable quantities of H2O2 after two hours of polarization, with concentrations increasing with decreasing potentials up to −1000 mV. The detection and quantification of ROS in a clinical setting could help us better understand the role of ROS in the inflammatory response as well as their impact on corrosion behavior of biomedical alloys.

In this paper, MoS2 was used as a band-suitable semiconductor to construct the Bi2O3/MoS2 heterostructured photocatalysts for the first time via a deposition-hydrothermal method. The XRD, SEM and HRTEM analysis indicated that the surface of Bi2O3 was decorated with MoS2 nanoparticles and Bi2O3/MoS2 heterojunctions were formed. The performances on photocatalytic degradation of methylene blue (MB) and tetracycline (TC) were evaluated under visible light irradiation. The results demonstrated that the Bi2O3/MoS2 heterojunctions displayed remarkably improved photocatalytic activity for both MB and TC degradation, compared to the base material (Bi2O3). Specifically, as the molar ratio of MoS2 was 23.81%, the obtained Bi2O3/MoS2-23.81 heterojunctions exhibited promising photocatalytic activities, and approximately 100% MB and 97% TC were degraded within 100 min, respectively. The superior photocatalytic activity was mainly attributed to its large surface area, high visible-light harvesting and the efficient separation of photogenerated electrons and holes caused by the unique heterojunction architecture. Notably, the Bi2O3/MoS2 heterojunctions showed remarkable stability in recycling photocatatlytic experiments. The active species trapping and terephthalic acid (TA) fluorescence experiments indicated that the •OH was the major reactive oxidizing species for MB degradation. Furthermore, the intermediates were detected by UPLC-MS spectrometry and the possible degradation pathways for MB and TC were proposed. Finally, a possible reaction mechanism of Bi2O3/MoS2 heterojunctions for the photodegradation MB was also proposed. This interesting interfacial architecture strategy will provide useful insights for designing and fabricating new class of binary heterojunctions with high-efficient photocatalytic activity towards practical application.

Photocatalytic activity of commercial zinc oxide nanoparticles (ZnO) has been investigated and its photocatalytic efficiency improved by loading silver (Ag/ZnO) using UV light. Ag-doping onto ZnO, various mole % (1, 3, 5, 7 and 9) of silver has been investigated for the photoactivity of the doped material in acid yellow 99 (AY99) degradation. The effect of operation parameters such as pH, catalyst dosage, and initial dye concentration was estimated. The optical band gap of the samples was found to be 3.36 eV for ZnO and 3.34 eV for Ag/ZnO (7%), which proves the change in the acceptor level induced by the Ag atoms. Optimal experimental conditions on catalysts amount, pH value, illumination time, and dye concentration have been determined. These catalysts were characterized for surface area, particle size and crystallinity. The mineralization of AY99 has been confirmed by Chemical Oxygen Demand measurements. Furthermore, the kinetics and scavengers of the reactive species during the degradation were also investigated. It was found that the degradation of AY99 fitted the pseudo first-order kinetics and OH radicals were the main species. Formation of OH free radicals during irradiation is established by photoluminescence studies using terephthalic acid as examination molecule.

Self-assembled three-dimensional (3D) Bi2SiO5 microspheres were synthesized via a solvothermal method using glycerol as reaction media and NH3•H2O as pH adjustment. The growth of Bi2SiO5 crystal was influenced by the solvothermal time. During the preparation process, glycerol acts as a soft template to guide the formation of the hierarchical microspheres. The photocatalytic activities of Bi2SiO5 microspheres toward the degradation of Rhodamine B and phenol under light irradiation were evaluated. Bi2SiO5 microspheres display much higher photocatalytic activity than the Bi2SiO5 nanoplates. The high photocatalytic activity of hierarchical Bi2SiO5 microspheres can be ascribed to the enhanced light absorbance, the efficient separation of photo-generated electrons and holes and the large surface area. The main active species during the photocatalytic reaction are •OH and •O2−, proven by terephthalic acid photoluminescence probing technique and nitroblue tetrazolium (NBT) experiments. The Bi2SiO5 microspheres are stable during the photocatalytic reaction and can be used repeatedly.

Herein, high performance peroxidase-like activity of zinc and cobalt bi-metal metal-organic framework (ZnCo MOF) is reported and applied for the sensitive measurement of atropine. ZnCo MOF was synthesized by the reaction of 2-methylimidazole with Zn and Co (II) cations in aqueous media. The colorimetric and fluorometric experiments were applied to investigate the catalytic activity of obtained MOF, using o-phenylenediamine (OPD) and terephthalic acid (TA) peroxidase substrates, respectively. The results demonstrated the more efficient mimetic behavior of ZnCo MOF compared with common Zn or Co MOFs. Besides, it was found that atropine hindered the catalytic action of ZnCo MOF and this effect was intensified by increasing the atropine concentration. So, it was considered to design a sensitive analytical assay for atropine detection. To assure a high specific recognition, molecularly imprinted polymer (MIP)-based extraction using magnetic graphene oxide supports was applied to extract atropine before its determination. The combination between the high specific extraction and great catalytic activity of ZnCo MOF led to the ultrasensitive and reliable determination of atropine. The best linear range of calibration graph was achieved using fluorometric detection system for 0.1–45 ng mL−1 atropine concentrations, and detection limit (3Sb/m) was 27 pg mL−1. The relative standard deviations (RSD %) for the determination of 1, and 10 ng mL−1 atropine (n = 5) were 2.13% and 3.08%, respectively. The explained fluorometric assay was examined for the measurement of atropine in biological fluids (Recoveries were in the range of 95.90–103.57%), and the results were validated by an official method.

Electrospinning and solvothermal methods were used to synthesize RGO/In2TiO5 nanobelts. The prepared samples were characterized with XRD, SEM, UV–vis DRS, N2 adsorption-desorption isotherms, FT-IR and Raman spectroscopy. The results have shown that the samples presented an orthorhombic structure without any secondary phase, and the morphology was not noticeably changed after coupling RGO. The RGO (1 wt%)/In2TiO5 nanobelts showed the highest photocatalytic activity. After 120 min of simulated sunlight irradiation, the degradation rate of RhB was up to 97.5%. Meanwhile, RGO/In2TiO5 nanobelts showed excellent photocatalytic degradation property for fluoroquinolone antibiotic levofloxacin (LEV). The increased electrons and holes separation, enhanced active sites and improved light acquisition were the reasons for the outstanding photocatalytic performances of the photocatalyst. Moreover, terephthalic acid photoluminescence (TA-PL) experiments confirmed that the hydroxyl radicals ( OH) were generated during the photocatalysis processes. The enhanced photocatalytic activity allows RGO/In2TiO5 nanobelts to be a promising candidate to treat antibiotic medical wastewater field in the future.

In this paper, a highly efficient photocatalyst of ZnTCPP sensitized g-C3N4 was successfully constructed via a facile thermal polycondensation method. The FT-IR and XRD data indicated that ZnTCPP molecules were successfully condensed on the surface of g-C3N4 through amide groups as the bridging units. The optimum 10%ZnTCPP/g-C3N4 composites exhibits excellent enhanced photocatalytic activity for decomposing both methylene blue (MB) and tetracycline (TC) under visible light with long-term reusability and elimination rates of 96% and 80.3%, respectively. The superior visible light photocatalytic performance was mainly attributed to the highly efficient separation of electron-hole pairs and the enhanced solar light utilization, as demonstrated by photoluminescence (PL), electrochemical impedance spectra (EIS), photocurrent responses, and UV–vis diffuse reflectance spectroscopy (DRS). The active species trapping and terephthalic acid (TA) fluorescence experiments indicated that OH was the dominating reactive oxidizing species for TC degradation. Furthermore, the possible photocatalytic degradation pathways for MB and TC have been proposed based on the UPLC-MS spectrometry. The excellent degradation efficiency of ZnTCPP/g-C3N4 reveals that it has great potential as photocatalysts for practical application to eliminate recalcitrant organic contaminants.

Self-doped TiO2 nanotube arrays (DNTA) were prepared for the electrooxidation of resistant organics. The anatase TiO2 NTAs had an improved carrier density and conductivity from Ti3+ doping, and the oxygen-evolution potential remained at a high value of 2.48 V versus the standard hydrogen electrode, and thus, achieved a highly enhanced removal efficiency of phenol. The second anodization could stabilize Ti3+ and improve the performance by removing surface TiO2 particles. Improper preparation parameters (i.e., a short anodization time, a high calcination temperature and cathodization current density) harmed the electrooxidation activity. Although boron-doped diamond (BDD) anodes performed best in removing phenol, DNTA exhibited a higher mineralization of phenol than Pt/Ti and BDD at 120 min because intermediates were oxidized once they are produced with DNTA. Mechanism investigations using reagents such as tert-butanol, oxalic acid, terephthalic acid, and coumarin showed that the DNTA mineralization resulted mainly from surface-bound OH, and the DNTA produced more than twice the amount of OH compared with BDD. The free OH on the BDD electrode was more conducive to initial substrate oxidation, whereas the adsorbed OH on the DNTA electrode mineralized the organics in situ. The preferential removal of p-substituted phenols on DNTA was attributed mainly to their electromigration and the aromatic intermediates that are hydrophobic were beneficial to mineralization.

Replacing fossil-C based plastics with those derived from renewable-C is one of the goals of the modern polymer industry. 2,5-Furan dicarboxylic acid (2,5-FDCA) is a candidate to substitute terephthalic acid as comonomer for polyesters. 2,5-FDCA is usually produced from C6 sugars. Carboxylation of 2-furancarboxylic acid (2-FCA) to 2,5-FDCA is an alternative synthetic approach to such monomer for polyethene furoate (PEF) preparation. In this work, several inorganic carbonates have been tested in the 2-FCA carboxylation in presence and absence of CO2. A key copper intermediate has been synthesized and fully characterized that is able to increase the acidity and, thus, the reactivity of 5-H towards a carbonate species. Carboxylation occurs at 93% yield in absence of CO2. The role of metal salts and CO2 were investigated. The conversion yield of 2-FCA into the dicarboxylic acid is related to the charge density on the metal cation, increasing with lower charge-density.

Concentrations of three monomers used in the manufacture of polyester resins for food cans, isophthalic acid (IPA), terephthalic acid (TA) and nadic acid (NA), and two oligomers were determined in canned food samples. All canned foods were purchased in local supermarkets in the United States. Concentrations of IPA and TA were determined to be from below the limit of detection in tomato sauce to 69 μg/kg in coconut milk, while the highest concentration of NA was found in pumpkin at 21 μg/kg. Estimated concentrations of oligomers in the food samples ranged from non-detect to 595 μg/kg. The influence of the storage time, lot type, and retail outlet on the migration concentrations was also investigated.

Gd and Sn co-doped BiFeO3 nanoparticles were synthesized by sol-gel route and Bi0.95Gd0.05Fe0.95Sn0.05O3/Nitrogen doped graphene nanohybrid (BGFSO/NG, where NG: 1%, 2%, 3%, 4%, 5%, 6%) were synthesized by sprinkling BGFSO nanoparticles and NG into ethanol solution followed by thermal drying. Structural and morphological properties of BiFeO3 (BFO) nanoparticles, BGFSO nanoparticles, NG and BGFSO/NG, were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The crystallite size BGFSO nanoparticle is about 20 nm. The photocatalytic activities of the as-prepared BiFeO3 (BFO) nanoparticles, BGFSO, NG and BGFSO/NG nanohybrid were measured by the degradation of methyl orange (MO) under simulated sunlight irradiation. BGFSO/N-G nanohybrid shows enhanced photocatalytic activity. The improved photocatalytic activity is attributed to the effective transfer of photogenerated electrons from nanoparticles NG nanosheets, consequently leads to an increased availability of h + for the photocatalytic reaction. Additionally, hydroxyl (⋅OH) radicals were detected by the photoluminescence method through terephthalic acid (TPA) as a probe molecule and are found to be generated on the irradiated BGFSO and BGFSO/NG.

Untreated terephthalic acid (TPA) wastewaters with high organic loads will cause severe environmental pollution problems. In this study, a lab-scale moving bed biofilm reactor, where biomass of Delftia sp. WL-3 is attached to polypropylene carrier elements, has been tested for TPA bioremediation at 25–27 °C. The system achieved stable operation after a short 15-day start-up period. During the operation period of 65 days, stable chemical oxygen demand (COD) and TPA removal efficiencies of 68% and 76% were maintained with an organic load rate (OLR) and hydraulic retention time of 2.5 kg COD·(m3·d)−1 and 24 h, respectively. In addition, the Scanning Electron Microscope (SEM) showed that high-densities of WL-3 biomass accumulated on the surface of the carrier and formed a rich biofilm, indicating polypropylene carrier can improve the degradation efficiency. On the contrary, the biodegradation ability of stain WL-3 without the polypropylene carrier declined significantly with removal efficiencies of 10% and 15% for COD and TPA. Furthermore, the system exhibited excellent robustness to different OLR and influent matrix ratios, indicating its potential for applications in the treatment of TPA-containment wastewater in the field.

A series of porous TiO2 photocatalysts are prepared, by systematically varying the preparation conditions (time, temperature, or pressure (i.e. filling ratio)), characterized, and evaluated in photocatalytic oxidation of toluene and methyl ethyl ketone (MEK) to explore preparation-property-performance relationships. A detailed characterization has been conducted via X-ray diffraction (XRD), N2 adsorption-desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), and UV–vis spectroscopy. Furthermore, hydroxyl radical ( OH) generation on the surface of TiO2 is measured by a photoluminescence (PL) method using terephthalic acid (TA) as probe molecule. All the hydrothermally-prepared samples possessed good crystallinity (79.5–89 %), large surface area (134.9–237.2 m2/g), small crystal size (5.9–10 nm), and mesoporous structure. SEM images revealed presence of macropores and marcochannels, and N2 adsorption-desorption and TEM analyses indicated a significant amount of mesopores. PL and XRD results demonstrated a good proportionality between surface area normalized OH generation and crystallinity. The complex interplay among various properties (especially crystallinity and surface area) led to appearance of activity optimums. Photocatalyst prepared at 12 h, 200 °C, and 80% filling ratio exhibited the best toluene and MEK removal efficiencies, which surpass those of P25 by factors of 2.08 and 1.85 times, respectively. The superior photocatalytic activity of developed TiO2 catalysts might be attributed to high surface area and existence of meso-/macropores that provide a large number of active sites, and facilitate light penetration and pollutants diffusion. The presented property-activity relationships can be utilized as potential design criteria for the development of new TiO2 photocatalysts for air purification.

The dissemination of technologies for poly(ethylene terephthalate) (PET) recycling is of paramount importance in the context of the plastics circular economy. One of the most promising alternatives is to use enzymes as catalysts for PET depolymerization to its monomers, but this route still needs improvement, especially regarding titer and productivity. In the present work, a sequential approach comprised of fractional factorial and central composite rotatable designs, the path of steepest ascent and one-way evaluation of variable effect, was performed to address these limitations, during assorted post-consumer PET (PC-PET) hydrolysis catalyzed by Humicola insolens cutinase. The highest terephthalic acid concentration and productivity during PC-PET hydrolysis were 100.9 mM (16.8 g/L) and 14.4 mM/day, corresponding to overall improvements of 10-fold and 20-fold, respectively. These data are among the best results described so far for enzyme-catalyzed hydrolysis of used PET packages. Also, the use of a single enzyme system, instead of multiple biocatalysts to achieve final conversion of PET to its monomers, lowers the process complexity and costs.

Hydroxymethylfurfural (HMF) is an industrially important chemical which is a starting material in the production of plenty of platform chemicals. In this study, a complete biotransformation of HMF was achieved using a novel isolate, Acinetobacter oleivorans S27. This strain could tolerate up to 3000 mg/L of HMF concentration and convert to other furan derivatives. The conversion products includes high-value chemicals like 5-hydroxymethyl-2-furancarboxylic acid (HMFCA), a known interleukin inhibitor and 2,5-furan dicarboxylic acid (FDCA), an alternate of terephthalic acid in polyester industries. The biotransformation efficiency was found to be 100%, as there is complete conversion of HMF to other chemicals. Most importantly, it is an environmental friendly process for the production of furan derivatives.

Chemical compounds bearing boron element have been included in more distinguished works with its increasing importance. In this work, boronic Schiff base compounds were synthesized from various amino acids and amino acid analogues. The nomenclatures of obtained structures can be presented as; (E)-3-((4-boronobenzylidene)amino)-3-((carboxymethyl)thio)propanoic acid (1); (E)-2-((4-boronobenzylidene)amino)terephthalic acid (2); (E)-2-((3-boronobenzylidene)amino)-4-methylpentanoic acid (3); (E)-2-((4-boronobenzylidene)amino)-4-methylpentanoic acid (4). The obtained boron compounds were characterized by a number of physical and chemical methods such FTIR, UV–Vis., 1H NMR, SEM-EDX, and TGA. Then the identified compounds were employed on Ishikawa endometrial cancer cells to investigate their cell viabilities. The expected results were evaluated by cytotoxic effects on cancer cell lines. For this purpose, solutions of the compounds were prepared at different concentrations (50 μM, 100 μM, 500 μM, and 1 mM) and applied according to the biological process. It has been found that all boron-containing compounds controllably killed cancer cells in different percentages. In addition to the anticancer application of boron-bearing molecules, the antioxidant activity was examined according to various reference substances such as BHT (Butylated hydroxy toluene), α-Toc (alpha-Tocopherol) and BHA (butylated hydroxy anisole). Significant properties were obtained from antioxidant investigations which applied by different methods such ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) Cation Radical Activity, DPPH (2,2-diphenyl picryl hydrazyl) Free Radical Activity, and CUPRAC (Cupric reducing antioxidant capacity).

A copper-centred metal-organic framework material MOF-101 with 2-bromine terephthalic acid as ligands was synthesized by solvothermal method at 70 °C and modified by loading Ag+ to improve the selective adsorption performance. The MOF-101 and Ag+/MOF-101 prepared were characterised by powder X-ray diffraction, X-ray fluorescence, Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. The adsorptive desulphurisation was quantified by adsorbing dibenzothiophene (DBT) from model oils. The loading of Ag+ enhanced the deep adsorptive desulfurization capacity for DBT and significantly weaken the adsorption competitiveness of toluene. As a result, the DBT concentration of model oil was reduced from 50 ppmS to 10.2 ppmS. Possible understandings were put forward to explain the adsorption performance of Ag+/MOF-101. The kinetics and isotherm data can be well-described by the pseudo-second-order kinetic model and the Langmuir model.

This article proposes a novel strategy for producing highly dispersed H3PW12O40 (HPW) on metal-organic frameworks (MOFs) via the anchoring action of amino groups originating from 2-amino terephthalic acid (APTA) in the MOF ligand. Under this method, amino groups are introduced into the linker of UiO-66 materials through a one-pot synthesis to disperse supported HPW, which has a negligible impact on the crystal structure of UiO-66. The acidic densities in the HPW/UiO-66 catalysts are effectively modified by adjusting the molar APTA/PTA (terephthalic acid) ratio in the mixed ligand and HPW loading. Consequently, the dispersion and stability of supported HPW are significantly enhanced, which make the as-prepared catalyst with 40 wt% of HPW present superior sec-butyl acetate (SBAC) yield (38.6 wt%) and selectivity (98 wt%) for the direct esterification of olefins. This strategy provides a new approach for preparing supported HPW with high dispersion and stability to be applied in olefin esterification.

Targeting CO2 capture at low pressure due to the partial pressure of CO2 in flue gases (0.01 MPa–0.02 MPa), a facile method was constructed to build functional UiO-66 structure via mixing ligands of terephthalic acid and 1,2,4-benzenetricarboxylic acid. The free -COOH from 1,2,4-benzenetricarboxylic acid could graft quantitative and dispersive deep eutectic solvents onto UiO-66 with reserved open metal sites for CO2 adsorption. Compared to 1,3,5-benzenetricarboxylic acid, mixing ligands by 1,2,4-benzenetricarboxylic acid preserved the stability of UiO-66 structure, which was more suitable for CO2 capture from flue gases. The active -NH2 and -OH groups from incorporated DES synergized with the intrinsic open metal sites to enhance the CO2 uptake at low pressure and improve adsorption selectivity of CO2/N2. At 298 K, the CO2 uptake of DES@UiO-66-COOH(0.05) was increased by 26% at 1 bar and 50% at 0.15 bar compared to UiO-66. In addition, the selectivity of CO2/N2 for DES@UiO-66-COOH(0.05) was 24.7 times as high as UiO-66 at low pressure. The strong interaction between guest CO2 and modified UiO-66 was confirmed by higher isosteric heats of adsorption (Qst) for DES-appended UiO-66. Even so, the sample could be regenerated at 373 K and vacuum, and could be recycled without drop of CO2 uptake after 6 times.