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Abstract Herein, we report a facile method for the synthesis of sulfonated coffee waste (CW-SO 3 H). The biosorbent was characterized using Scanning Electron Microscopy (SEM), Energy-dispersive X-ray Spectroscopy (EDS), Fourier-transform Infrared Spectroscopy (FTIR), Raman Spectroscopy, Thermogravimetric analysis (TGA) and Zeta potential measurements. The biosorbent was used for the biosorption of endocrine disrupting chemicals such as bisphenol A (BPA) and antibiotics such as sulfamethoxazole (SMX) from water. The calculated biosorption capacities of CW-SO 3 H were 271 mg/g and 256 mg/g towards the removal of BPA and SMX, respectively. The as synthesized biosorbent is capable to form π–π interaction and electrostatic interaction that allow the efficient biosorption of BPA and SMX. The Temkin isotherm model fits the experimental data better for BPA biosorption process, whereas the Temkin and Langmuir models explain the experimental data better for SMX biosorption process. The kinetic studies showed that the biosorption of BPA and SMX by CW-SO 3 H follows pseudo-second order kinetic model. The thermodynamic studies showed that the biosorption processes were spontaneous as well as exothermic in both cases. Therefore, CW-SO 3 H could be used as a promising biosorbent for the rapid removal of BPA and SMX from the wastewater. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Saw dust derived functionalized graphitic carbon was prepared successfully. • Better adsorbent than commercially available activated carbon. • Utilized towards the removal of emerging pollutants such as TC, SMX, and BPA. • H-bonding, electrostatic and π-π interaction adsorption mechanisms were proposed. Abstract Presence of antibiotic contaminants in drinking water is increasing in epidemic proportions in recent times. Here, we report a scalable and cost-effective approach to prepare sulfonated saw dust (SD-SO 3 H) derived from saw dust (SD) that exhibits high-capacity adsorbent properties for the removal of antibiotics such as Tetracycline (TC), Sulfamethoxazole (SMX), and endocrine-disruptive chemicals such as Bisphenol A (BPA). The adsorption capacities of SD-SO 3 H towards the removal of TC, SMX, and BPA are 270.53 mg/g, 295.06 mg/g, and 263.75 mg/g, respectively. The adsorption capacity of SD-SO 3 H is about 2 and 4 times higher than commercially available activated carbon towards the removal of SMX and BPA, respectively according to the literature. For TC, the adsorption capacity of SD-SO 3 H is comparable to the commercially available activated carbon. The adsorbent was characterized using Scanning Electron Microscopy (SEM), Energy-dispersive X-ray Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR), Raman Spectroscopy, Thermogravimetric analysis (TGA), and Zeta potential measurements. The effect of initial concentration, dosage, time, pH and temperature on the adsorption process was systematically investigated. Isotherms studies showed that the TC and SMX adsorption follow Langmuir isotherm whereas, BPA adsorption follows Freundlich isotherm. The kinetics data can be well defined by the pseudo-second order kinetic model. A thermodynamic study of adsorption showed that the TC adsorption process was endothermic while the SMX and BPA adsorption processes were exothermic, and the adsorption process was spontaneous in all cases. Altogether, SD-SO 3 H can be a scalable, cost-effective adsorbent for the efficient removal of TC, SMX and BPA from wastewater. [ABSTRACT FROM AUTHOR]

Abstract In this study, we report a facile method for the preparation of sulfonic acid functionalized carbonaceous adsorbent (TW-SO 3 H) from tea leaves. The adsorbent was characterized using Fourier-transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy-dispersive X-ray Spectroscopy (EDS), Thermogravimetric analysis (TGA), Raman Spectroscopy and Zeta potential measurements. The adsorbent was utilized for the adsorptive removal of antibiotics such as sulfamethoxazole (SMX) and endocrine disrupting chemicals such as bisphenol A (BPA) from water. The calculated adsorption capacities of TW-SO 3 H were 258.87 mg/g and 236.80 mg/g towards the removal of SMX and BPA, respectively at 25 °C. The new adsorbent has the ability to form electrostatic interaction and π–π stacking that allow the efficient adsorption of SMX and BPA. The Langmuir and Temkin isotherm models best fit the experimental data for the BPA and SMX adsorption processes, respectively. The results of the kinetic studies showed that the removal of SMX and BPA by TW-SO 3 H followed pseudo-second order kinetic model. A thermodynamic study indicated that the adsorption process was spontaneous as well as exothermic. The adsorbent was facilely regenerated and recycled for three cycles with a nominal loss of adsorption capacity. Our results indicated that TW-SO 3 H could be utilized as a promising adsorbent for the rapid removal of SMX and BPA from the contaminated water. [ABSTRACT FROM AUTHOR]

Graphical abstract Fullerene Stabilized Gold Nanoparticles Supported on TiO 2 for Enhanced Photocatalytic Degradation of Methyl Orange and the Catalytic Reduction of 4-nitrophenol. Highlights • Fullerene (C 60) mediates the formation of gold nanoparticles (AuNPs). • AuNPs bind to TiO 2 without any surface functionalization. • AuNPs-TiO 2 enhances the photocatalytic degradation of methyl orange. • AuNPs-TiO 2 catalyzes the reduction of 4-nitrophenol to 4-aminophenol. • AuNPs-TiO 2 demonstrates high cyclic stability to the photocatalysis. Abstract A facile method for the synthesis of gold nanoparticles (AuNPs) supported on TiO 2 is reported. The average size of the TiO 2 supported AuNPs was found to be about 8 nm, which was measured by the transmission electron microscopy. The TiO 2 supported AuNPs exhibited enhanced photocatalytic degradation of methyl orange (MO) and catalytic reduction of 4-nitrophenol (4-NP) in water. Both the photocatalytic degradation of MO and the catalytic reduction of 4-NP were influenced by the size and the percent AuNPs loading. Compared to the pristine TiO 2 the nanocomposite having 4.76 wt% AuNPs showed about twice and 132 times faster activity in the photodegradation of MO and the reduction of 4-NP, respectively The cyclic stability of the nanocomposite was examined for ten cycles and it was found that the catalyst is fairly active throughout the cycles. Further, the photocatalytic generation of hydroxyl radical (OH) was confirmed through the terephthalic acid photoluminescence tests. [ABSTRACT FROM AUTHOR]

There has been growing interest in making adsorbents more cost-effective and feasible in low resource areas by using material that is cheap or would usually be considered waste. In the present study, a high-capacity regenerable adsorbent is synthesized by the treatment of waste tire rubber (WTR) with concentrated sulfuric acid. The sulfuric acid reflux carbonized as well as functionalized the WTR with the sulfonic acid group. The as-prepared sulfonated carbonaceous WTR was used for the removal of organic dyes and antibiotic viz. methylene blue (MB), methyl orange (MO) and Tetracycline (TC) from water. The maximum adsorption capacity was found to be about 833, 588, and 303 mg/g towards MB, MO, and TC, respectively. The adsorption of MB, MO, and TC from the tap water matrix was also performed and shown to maintain similar adsorption capacities as the deionized water. In addition, a packed glass column was prepared to demonstrate the continuous adsorption of MB and TC from the tap water matrix. The regeneration of the column was achieved by using mixture of aqueous and organic solvents with dissolved NaOH and it was demonstrated that the adsorbent not only recovered but also increased its adsorption capacity after every time it was regenerated. [ABSTRACT FROM AUTHOR]

Herein, we report a novel benzoylated-cotton and multiwalled carbon nanotubes (BC-MWCNT) composite that exhibits efficient electrocatalytic properties to produce reactive oxygen species (ROS) in water. The BC-MWCNT was deposited on a fluoride-doped tin oxide (FTO) electrode to probe its electrochemical properties. The ROS produced through this approach were exploited towards the degradation of Methyl Orange (MO) dye. The BC-MWCNT electrode produced ROS at a −1.0 V potential, as indicated by the electrochemical degradation of MO dye solutions by 96% at pH 7.4 in 60 min. Experiments performed by varying the pH and electrolyte concentrations produced dramatic changes in the kinetics of the reaction, increasing degradation to 100% and shortening reaction time to 4 min with optimal conditions at pH 3. [ABSTRACT FROM AUTHOR]

We demonstrate sodium rhodizonate as a novel dual-functional reducing and stabilizing agent to form gold nanoparticles (AuNPs) of controlled size based on temperature. At room temperature (ca. 23 °C), the method generates AuNPs with an average size of ∼11 nm, whereas at 80 °C, it forms AuNPs with an average size of ∼7 nm. The rhodizonate-stabilized AuNPs readily bind to cellulose fibers (CF) while maintaining a high catalytic activity. The catalytic activity of the CF-supported AuNPs nanocomposites is demonstrated by the reduction of 4-nitrophenol (4-NP) and organic dyes such as methyl orange (MO), methylene blue (MB) in water. A glass column-based continuous catalytic reduction and its recyclability is also demonstrated for practical applications. [ABSTRACT FROM AUTHOR]

In this study, the preparation of sulfonated resorcinol-formaldehyde (RF-SO 3 H) microspheres having high adsorption capacity towards organic dyes is reported. The ability for facile regeneration of the RF-SO 3 H microspheres is also demonstrated, which may allow for the re-use of the adsorbent as well the re-utilization of the dyes. The RF-SO 3 H microspheres exhibited high adsorption capacity towards the anionic and cationic organic dyes such as methyl orange (MO) and methylene blue (MB) from the water. The equilibrium adsorption capacity was measured to be 710 mg/g and 511 mg/g towards MO, and MB, respectively. The effect of pH, contact time, and initial concentration of dyes was analyzed and shown that the adsorption capacity for MO increases in acidic pH and vice versa for MB. The adsorption of MO and MB from tap water was also performed and shown to maintain similar adsorption capacity as in the deionized water. In addition, a packed glass column was prepared to demonstrate the continuous adsorption of MO and MB under flow conditions. Regeneration of the column was achieved by using organic solvents and it was demonstrated that the adsorbent not only recovered but also increased its adsorption capacity after every time it was regenerated. [ABSTRACT FROM AUTHOR]

Abstract: Hydrogen gas physisorption in two distinct dinuclear Pt(II) metallacycles was investigated with 2H nuclear magnetic resonance (NMR) spectroscopy. Hydrogen adsorption isotherm data and 2H NMR spectroscopy indicated that hydrogen storage occurs via condensation within the cavities of one of the macrocycles and at the interstitial sites in the other. In addition, this study further supports the notion that heat of adsorption and pore size play critical roles in hydrogen storage. [Copyright &y& Elsevier]

Graphical abstract Modification of peanut-shell into a high-capacity adsorbent using the sulfuric acid reflux technique for the removal of methylene blue and tetracycline from water. Highlights • Sulfonated peanut shell (PNS-SO 3 H) was prepared by sulfuric acid reflux. • PNS-SO 3 H adsorbed methylene blue (MB) up to 1250 mg/g. • PNS-SO 3 H adsorbed tetracycline (TC) up to 303 mg/g. • PNS-SO 3 H can adsorb MB and TC from tap water. • Column packed with PNS-SO 3 H can continuously filter MB from tap water. Abstract Preparation of economically and environmentally viable adsorbents out of biomass has achieved immense interest for the water treatment purposes. This study reported the synthesis of a low-cost and high-capacity adsorbent viz. sulfonated peanut shells (PNS-SO 3 H) by a facile sulfuric acid (H 2 SO 4) reflux technique. The concentrated H 2 SO 4 reflux resulted in the carbonization and sulfonation of the peanut shell. Organic pollutants e.g. methylene blue (MB) and tetracycline (TC) were removed from water by the PNS-SO 3 H. The adsorption characteristics were evaluated as the function of pH, time, initial adsorbate concentration, and temperature in batch adsorption tests. At basic pH, MB showed an increasing trend of adsorption capacity, whereas TC demonstrated the opposite trend. The maximum adsorption capacity was found to be 1250 and 303 mg/g for MB and TC, respectively. In comparison to the pristine peanut shell, the PNS-SO3H demonstrated about 100 and 40 times higher adsorption capacity for MB and TC, respectively. The batch adsorption results were in good fit with the Langmuir isotherm model and the adsorption kinetics followed pseudo-second-order kinetics. The adsorption of MB and TC was found to be endothermic and thereby an increased adsorption capacity was obtained at elevated temperature. The adsorption performance of MB and TC from tap water was also studied and similar adsorption behavior as deionized water was obtained. A packed column was prepared with PNS-SO 3 H for the filtration of 20 ppm MB solution from tap water. The column was able to filter 36 liters of MB solution with 100% removal efficiency. [ABSTRACT FROM AUTHOR]

The development of cost-effective carbon-shell coated metal-based nanocatalysts is currently a highly desirable goal towards the fabrication of more sustainable non-precious nanocatalysts. Herein, we design an easy, cheap, scalable, and eco-friendly carbothermal reduction strategy to develop core-shell structured metallic iron nanoparticles using coffee waste grounds as starting renewable materials (Fe@BMC). The structural properties of the as-synthesized nanoparticles were nicely tuned by varying the reaction temperature. Remarkably, ultrathin carbon-shell coated metallic iron nanoparticles were obtained at 800 °C, which was clearly elucidated by the HRTEM, XRD, and XPS measurements. The Fe-800 °C@BMC nanocatalyst showed excellent properties as an ORR electrocatalyst with an onset potential of 0.93 V vs RHE, keeping 90% of the initial current applied after the 20000s. Noticeably, the Fe-800 °C@BMC carbon-shell nanostructures delivered a Pt-like performance with a very low onset potential of −25 mV vs RHE, an overpotential of 75 mV at a current density of 10 mA cm−2 and an ultrahigh stability to keep the 99% of the initial current applied after 20000s, behaving like one of the most efficient HER core-shell structured non-precious electrocatalysts reported up to now. Also, the Fenton like catalytic studies revealed that the Fe-800 °C@BMC nanocatalyst was so far the most active catalyst for the degradation of tetracycline (TC) antibiotic allowing the degradation of 95.72% of TC in 45 min with a higher reaction rate constant of 0.068 min−1. The impressive catalytic behavior of the Fe-800 °C@BMC nanocatalyst was attributed to the hierarchically porous carbon network as well as to the synergistic interaction between the encapsulated metallic iron core and the ultrathin carbon shell, which regulate the adsorption energy of the reactive species. The present work offers new insights into the development of scalable and high-performance tri-functional catalysts through a sustainable and low-cost synthetic route. Image 1 [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel synthetic methodology of MOF derived nanosized catalysts was developed. • Co@C nanocatalyst was highly catalytically active for PMS activation. • Ni@C demonstrated remarkable HER electrocatalytic properties. • Ni@C showed low onset potential of 61 mV and Tafel slope of 82 mV‧dec−1. • Ni@C showed a low overpotential of 286 mV to reach 10 mA‧cm−2. Synthesis of high-efficiency metal catalysts and their application in catalyzing critical chemical processes holds the key to the sustainable supply of water and energy. However, reaction-induced atomistic modifications of nanoclusters often result in reduced stability and efficacy. Herein, we report a highly active and multifunctional transition metal nanocatalysts encapsulated in porous carbon network (M@C where M = Cu, Ni, Fe, Co) prepared by leveraging the sacrificial templating properties of metal-organic frameworks (MOFs). The as-synthesized M@C nanocatalysts were employed for oxidative degradation of organic pollutants and electrocatalytic hydrogen generation. Fenton like catalytic studies revealed that the nanocatalysts were highly active and reusable following the order of Co@C > Fe@C > Cu@C > Ni@C. On the other hand, Ni@C electrocatalyst displayed superior activity towards hydrogen evolution reaction as compared to others, delivering a low onset potential of 61 mV, Tafel slope of 82 mV/dec and an overpotential of 286 mV at 10 mA‧cm−2. The activity was essentially unchanged even after 500 cycles, suggesting the long‐term stability under acidic conditions. The impressive multifunctional catalytic performances of M@C nanocatalysts are attributed to their unique porous carbon matrix doped by transition metal nanoparticles which provide a large number of interconnected catalytically active sites. [ABSTRACT FROM AUTHOR]

Development of photocatalytic paint based on TiO 2 nanoparticles and photopolymer resin for the degradation of organic pollutants in water under ultraviolet and sunlight irradiation. • Development of photocatalytic paint based on TiO 2 and photopolymer resin. • Applicability of the paint on various solid substrates. • Photocatalytic activity of the paint to degrade organic pollutants. • Efficient degradation of organic pollutants with high cyclic stability. • Generation of hydroxyl radicals under sunlight irradiation. While the use of TiO2 nanoparticles in the form of slurry/suspension requires energy-intensive separation processes, its immobilization in solid support may open new opportunities in the area of sustainable water treatment technologies. In this study, a novel method for the development of photocatalytic paint based on TiO 2 nanoparticles and acrylate-based photopolymer resin is reported. The paint (TiO 2 @polymer) was applied on substrates such as plastic petri dish and glass jar, which was polymerized/solidified by ultraviolet light irradiation. The painted petri dish and glass jar were used for the photocatalytic degradation of model organic pollutants viz. methyl orange (MO), methylene blue (MB), and indole in deionized water, simulated fresh drinking water, and tap water matrices. The photocatalytic degradation studies were performed under sunlight and UV-B light were used for. The sunlight-assisted photocatalytic degradation of MO and MB was found to be faster and more efficient than the UV-B light-assisted ones. Under UV-B light irradiation, it took 120 min to degrade about 80% of 6 ppm MB solution, whereas under sunlight irradiation it took 60 min to degrade about 90% of the same MB solution. The photocatalytic paint generated hydroxyl radical (·OH) under the UV-B and sunlight irradiation, which was studied by the terephthalic acid fluorescence tests. Further, the potential release of TiO 2 during the exposure to UV irradiation was studied by single particle ICP-MS analysis. [ABSTRACT FROM AUTHOR]

In this report, highly crystalline and well-dispersed nano-sized nickel metal organic framework (MOFs) was decorated over graphene oxide (GO) and carbon nanotubes (CNTs) platforms to form hybrid nanocomposites. These as-synthesized hybrid nanocomposites were synthesized through a one-pot green solvothermal method. The prepared nanocomposites were characterized by SEM, TEM, EDS, XRD, FT-IR, Raman and TGA techniques. XRD analysis revealed the crystalline structure of the hybrid nanocomposites. Morphological and elemental studies also verified successful decoration of nickel-benzene dicarboxylate (Ni-BDC) MOFs over GO and CNT platforms. Chemical analysis collected through IR, and thermal analysis collected through TGA technique, illustrated the presence of all the components in the hybrid nanomaterials. Methylene blue (MB) was used as a model organic pollutant to analyze the adsorption capacity of the prepared nanocomposites. According to the findings, a strong interaction exists between the MB molecule and the developed adsorbents at which due to the synergistic effect, the hybrid nanocomposites show several times higher adsorption capacity compared to that of parent materials. This improvement can be due to several reasons: high surface area of the MOFs in the composites resulting from the smaller size of MOFs, presence of the pores formed between the MOFs and the platforms and different morphological characteristic of Ni-BDC MOFs in hybrid nanocomposites, compared to bare Ni-BDC MOFs. Furthermore, the isotherm and kinetic studies revealed that the adsorption of MB onto the newly prepared adsorbents could best be explained by the Langmuir and Pseudo-second order kinetic models. A regeneration study demonstrated the highly stable nature of the hybrid nanocomposites. Unlabelled Image • Nano scaled Ni MOFs are synthesized using GO and CNTs platforms. • Offers a new platform for decorating nano-size MOFs over the carbon nanostructures • The developed nanomaterials are used for water remediation. • Remarkable adsorption capacity of 222 mg/g for MB adsorption • The MB adsorption process can be described by π–π interaction. [ABSTRACT FROM AUTHOR]