Abstract: Gallic acid (GA) is a polyphenols compound commonly present in wastewater that immensely affects aquatic and human life. GA is also responsible for the inhibitory effects on the microbial activity in the soil, thereby decreasing the fertility of the soil. Therefore, the removal of GA from the wastewater is necessary to combat such issues. The present study focused on the synthesis of reduced graphene oxide (rGO) incorporated bimetallic (Cu/Bi) based nanorods (r-GO-Cu/Bi-NRs) and their photocatalytic applications. Incorporating GO within the CuBi2O4-NRs might decrease the bandgap value, thereby increasing the interfacial charge transfer. Moreover, GO increased the reactive sites and oxygen defects onto the r-GO-Cu/Bi-NRs that led to the separation rate of the photo-induced charge carriers and migration, thereby enhancing the photodegradation ability of the synthesized r-GO-Cu/Bi-NRs. The synthesis process of the r-GO-Cu/Bi-NRs is facile, novel, and economically viable for the photocatalytic degradation of organic pollutants.

Abstract: A promising sustainable energy storage characteristic is achieved in redox additive electrolyte by developing strict blend of one dimensional (1D) and two dimensional (2D) structures. Hydrothermal reaction is followed to obtain the desired morphology. Two dimensional (2D) reduced graphene oxide (rGO) is added into the redox reaction between potassium permanganate and sodium nitrite to obtain nanocomposite comprising 1D and 2D blended structures of MnO2/rGO. Their structures and morphologies are studied by XRD, Raman and HRTEM analyses, respectively. The pseudocapacitive behaviour is studied in a redox additive electrolyte comprising KOH and K3Fe(CN)(6). The effect of electrolytic concentration was studied by varying the concentration of K3Fe(CN)6. The specific capacity is considerably enhanced up to 1741 F/g, 8.75 A/g with increase in concentration of K3Fe (CN)6. The role of redox couple [Fe(CN)(6)](3)-/[Fe(CN)(6)](4)-played a key role in adding the charge movement across the electrode which tuned well with the manganese ions to obtain one of the most promising pseudo-capacitances from the developed 1D and 2D blended structures of MnO2/rGO. For in-depth analysis of Fe ions movement, a symmetric supercapacitor cell is constructed to achieve a commendable specific capacitance of 216 F/g at 3.75 A/g. Prolong cycling hinted decreasing electrolytic interfacial layers resulting in fast reversible ki-netics of Fe(III) -> Fe(II) ions to achieve astonishing capacity retention of 127% after 3000 cycles.

Abstract: In this work, crystal facets, bandgap, size and shape of reduced graphene oxide (rGO) modified anatase {001} black TiO2 nanosheets (rGO-B-TiO2 NSTs) were tailored for the photocatalytic oxidation of ethylene under high humidity content. XRD, Raman and HR-TEM analyses confirm that rGO-B-TiO2 NSTs have a 94 % of exposed {001} facets with high number of oxygen vacancies. In addition, rGO-B-TiO2 NSTs exhibit increased values of surface area and porosity compared to its pristine form. A 48 and 34 mu mol g(-1) of ethylene are adsorbed at the surface of rGO-B-TiO2 NSTs in the absence and in the presence of humidity, respectively. In addition, operando DRIFTS analyses provide the insight of surface interactions between ethylene molecules and adsorption sites of rGO-B-TiO2 NSTs. The photocatalytic removal efficiencies of the synthesized materials under both UV and visible light irradiation proceed as follows: rGO-B-TiO2 NSTs > B-TiO2 NSTs > TiO2 NSTs > commercial TiO2 NPs. Further, ethylene is very quickly photocatalytic oxidized when rGO-B-TiO2 NSTs is applied under UV light irradiation, having a 72 and 92 % ethylene removal in the absence and in the presence of humidity, respectively. Moreover, a 48 and 58 % of ethylene removal takes place in the absence and presence of humidity under visible light irradiation, respectively. Results indicate that rGO-B-TiO2 NSTs boost the photocatalytic activity through their virtue of visible-light absorption properties (Bandgap = 2.61 eV) and the rapid electron-hole separation at the rGO {0 0 1} black TiO2 NSTs interfaces. Such findings are confirmed through UV-visible diffused reflectance, photoelectrochemical and photoluminescence analyses. Nanosheets made of rGO modified {0 0 1} black TiO2 could be used as an effective photocatalyst for the removal of ethylene from large volume fruit storage areas by exploiting a simple light source in the presence of high content of humidity.

Abstract: We report the synthesis of a new range of ferrihydrite-graphene oxide (FH-GO) foams using chitosan as cross linker, with varying iron content (5 wt%, 10 wt%, and 20 wt% of FH) as highly efficient adsorbents for the removal of arsenic (III) (As(III)) in an aqueous solution. The sonochemical methods were adopted to synthesize various FH-GO foams and were further characterized by XRD, SEM, TEM, FTIR, Raman, and XPS techniques. The synthesized materials were used for the removal of As(III) in both batch and fixed bed absorbent column methods. The adsorption isotherm results showed that the 10 wt% of FH-GO foams demonstrated a superior adsorbent for the As(III) with high adsorption capacities than that of the other two FH-GO foams (5 wt% and 20 wt% of FH). Moreover, 10 wt% of FH-GO foams was also demonstrated to be nearly a complete (>98.4%) removal of As(III) ions at neutral pH 7. The adsorption isotherm fitted very well with the Langmuir model with the highest accuracy data for all the synthesized adsorbent materials. In addition, the fixed bed absorbent column method was also adopted for the removal of As(III) ions in the water sample, which showed > 99.2% of removal efficiency. The outstanding adsorption capabilities, along with their easy and low-cost synthesis, make these kinds of adsorbents extremely capable for commercial applications in wastewater treatment and drinking water purification.