Competitive Langmuir Model for Dye Mixture Adsorption: Disagreement between Theoretical Ground and Application Condition.

Precise prediction of adsorption in a multicomponent system is vital for successful design of dye-contaminated industrial wastewater treatment processes. The present work looks for the reason behind the failure of the competitive Langmuir model (CLM) to describe adsorption in such systems, while the Langmuir model (LM) successfully describes the process for a single dye solution. With that end, derivations of LM and CLM have been revisited, and a criterion for the universality of active sites has been defined.

Sunlight-activated heterostructure MoS/CdS nanocomposite photocatalyst with enhanced photocatalytic activity: band alignment and mechanism study.

A high recombination rate is a major limiting factor in photocatalysis. Mitigating recombination through material engineering and photocatalyst optimization is key to enhancing photocatalytic performance. In this study, a heterostructure MoS/CdS nanocomposite was synthesized through a hydrothermal method in a Teflon-lined autoclave subjected to a temperature of 200 °C for 16 hours.

Langmuir Adsorption Kinetics in Liquid Media: Interface Reaction Model.

Adsorption kinetic equation has been derived assuming that the process follows the behavior of a heterogeneous chemical reaction at the solid-liquid interface. This equation is converted into the Langmuir isotherm at equilibrium and describes well the unsteady-state adsorption process. Based on that, a working equation has been developed, which gives adsorption-rate-constant independent of operating parameters including concentration.

A novel highly selective electrochemical chlorobenzene sensor based on ternary oxide RuO/ZnO/TiO nanocomposites.

A novel electrochemical (EC) chlorobenzene (CBZ) sensor was fabricated using a ternary oxide RuO/ZnO/TiO nanocomposite (NC)-decorated glassy carbon electrode (GCE). The nanoparticles (NPs) were synthesized by a wet-chemical method and characterized by X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), and ultraviolet-visible (UV-vis) spectroscopy. The synthesized RuO/ZnO/TiO NC was layered as thin film on a GCE with Nafion (5% suspension in ethanol) adhesive, and the as-prepared sensor was subjected to CBZ analysis using an electrochemical approach.

Facile one-pot synthesis of heterostructure SnO/ZnO photocatalyst for enhanced photocatalytic degradation of organic dye.

In this work, heterostructure SnO/ZnO nanocomposite photocatalyst was prepared by a straightforward one step polyol method. The resulting photocatalysts were characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption analyses, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). The results showed that the synthesized SnO/ZnO nanocomposites possessed mesoporous wurtzite ZnO and cassiterite SnO nanocrystallites.

Electrochemical detection of 2-nitrophenol using a heterostructure ZnO/RuO nanoparticle modified glassy carbon electrode.

A highly selective chemisensor for 2-nitrophenol detection was fabricated using ZnO/RuO nanoparticles (NPs) synthesized by impregnation method. The as-synthesized NPs were characterized through UV-vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), Energy dispersive X-ray spectroscopy (EDS), FTIR and X-ray diffraction (XRD). A glassy carbon electrode was modified with as-synthesized ZnO/RuO nanoparticles and utilized as a chemical sensor for the detection of 2-nitrophenol.

Improved photocatalytic activity in RuO2-ZnO nanoparticulate heterostructures due to inhomogeneous space charge effects.

New 2-6 wt% RuO2-ZnO heterojunction nanocatalysts were synthesized by a straightforward two-step procedure. They were composed of a porous network of aggregated 25 nm wurtzite ZnO nanocrystallites modified with RuO2 and showed enhanced light absorption in the visible region due to surface plasmon resonance. In order to investigate the energetic structure of the photocatalyst XPS core line and valence band spectra of in situ in UHV prepared heterointerfaces were compared to results obtained from the particles.

Nanostructured SnO2-ZnO heterojunction photocatalysts showing enhanced photocatalytic activity for the degradation of organic dyes.

Nanoporous SnO(2)-ZnO heterojunction nanocatalyst was prepared by a straightforward two-step procedure involving, first, the synthesis of nanosized SnO(2) particles by homogeneous precipitation combined with a hydrothermal treatment and, second, the reaction of the as-prepared SnO(2) particles with zinc acetate followed by calcination at 500 °C. The resulting nanocatalysts were characterized by X-ray diffraction (XRD), FTIR, Raman, X-ray photoelectron spectroscopy (XPS), nitrogen adsorption-desorption analyses, transmission electron microscopy (TEM), and UV-vis diffuse reflectance spectroscopy. The SnO(2)-ZnO photocatalyst was made of a mesoporous network of aggregated wurtzite ZnO and cassiterite SnO(2) nanocrystallites, the size of which was estimated to be 27 and 4.

Adsorption of methylene blue from aqueous solution by jackfruit (Artocarpus heteropyllus) leaf powder: A fixed-bed column study.

Continuous fixed-bed studies were undertaken to evaluate the efficiency of jackfruit leaf powder (JLP) as an adsorbent for the removal of methylene blue (MB) from aqueous solution under the effect of various process parameters like bed depth (5-10cm), flow rate (30-50mL/min) and initial MB concentrations (100-300mg/L). The pH at point of zero charge (pH(PZC)) of the adsorbent was determined by the titration method and a value of 3.9 was obtained.

Adsorptive removal of methylene blue by tea waste.

The potentiality of tea waste for the adsorptive removal of methylene blue, a cationic dye, from aqueous solution was studied. Batch kinetics and isotherm studies were carried out under varying experimental conditions of contact time, initial methylene blue concentration, adsorbent dosage and pH. The nature of the possible adsorbent and methylene blue interactions was examined by the FTIR technique.