Decoration of ZnO surface with tiny sulfide-based nanoparticles for improve photocatalytic degradation efficiency.

Modifying wide band gap ZnO nanoparticles surface by combine narrow bandgap semiconductors is a novel route to promote the ZnO to diverse applications. Herein, different metal sulfides (CdS, Ag2S and Bi2S3) were decorated on ZnO surface using facile a chemical route for photocatalytic application. Crystal structure, surface morphology and optical changes for the surface modified ZnO were studied by using various characterization techniques. The XRD spectra exhibited mixed phase of decorated metal sulfide nanoparticles along with strong pattens of hexagonal structure ZnO. The SEM images were confirmed that tiny CdS, Ag2S and Bi2S3 sulfide nanoparticles are well decorated on ZnO hexagonal rods surface. Band gap of the ZnO was tuned into visible region by modifying the surface by the sulfide nanoparticles. Textile industry-based crystal violet (CV) dye was used as a model pollutant to evaluate the photocatalytic activity of sulfides decorated well-crystalline ZnO photocatalysts under natural sunlight. Among the three catalysts, the Ag2S decorated ZnO achieved greatest photodegradation efficiency of 94.1% for degradation of the CV dye with rate constant value of 0.050. The highest catalytic activity may be related to Ag2S acting a significant part in reducing bandgap and boosting hole, superoxide radical, and hydroxyl radical formation, which inhibits recombination, hence enhancing the photocatalyst's efficacy, activity, and also stability.

RGO nanosheet wrapped ß-phase NiCu2S nanorods for advanced supercapacitor applications.

A new integration strategy of transition metal sulfide with carbon-based materials is used to boost its catalytic property and electrochemical performances in supercapacitor application. Herein, crystalline reduced graphene oxide (rGO) wrapped ternary metal sulfide nanorod composites with different rGO ratios are synthesized using hydrothermal technique and are compared for their physical, chemical, and electrochemical performances. It is found that their properties are tuned by the weight ratios of rGO. The electrochemical investigations reveal that ß-NiCu2S/rGO nanocomposite electrode with 0.15 wt.% of rGO is found to possess maximum specific capacitance of 1583 F g-1 at current density of 15 mA g-1 in aqueous electrolyte medium. The same electrode shows excellent cycling stability with capacitance retention of 89% after 5000 charging/discharging cycles. The reproducibility test performed on NiCu2S/rGO nanocomposite electrode with 0.15 wt.% of rGO indicates that it has high reproducible capacitive response and rate capability. Thus, the present work demonstrates that the ß-NiCu2S/rGO nanocomposite can serve as a potential electrode material for developing supercapacitor energy storage system.

Cerium-based metal sulfide derived nanocomposite-embedded rGO as an efficient catalyst for photocatalytic application.

Reduced graphene oxide (rGO) with metal sulfides is an efficient photocatalyst for treating textile effluent. Herein, a hydrothermal technique was used to synthesize transition metal sulfide with rGO nanocomposite. Under 120 min of sunlight exposure, the cerium-nickel sulfide/rGO nanocomposite (Ce2S3-NiS2/rGO) photodegraded the methyl orange (MO) dye with an efficiency of 89.1% which is significantly higher than that of bare nickel sulfide (NiS2) and cerium sulfide (Ce2S3) photocatalysts. Moreover, another model pollutant dye bromophenol blue (BP) was treated under the same experimental condition, and it has achieved about 84.2% degradation efficiency. The combination of NiS2 and Ce2S3 improves the separation efficiency of photogenerated carriers, resulting in improved photocatalytic activity. In addition, ternary metal sulfide with rGO increases pollutant adsorption and electron-hole photogenerated pairs. Therefore, the mechanism of photocatalytic Ce2S3-NiS2/rGO is investigated in detail. This research could pave the way for the development of capable and adaptable Ce2S3-NiS2/rGO photocatalysts for environmental remediation.

Biomimetic development of chitosan and sodium alginate-based nanocomposites contains zirconia for tissue engineering applications.

Nanostructured materials possess unique structural and functional properties that play a crucial position in tissue engineering applications. Present investigation is aimed to synthesize chitosan-sodium alginate (CS) nanocomposite using hydrothermally prepared zirconia nanoparticles. In this, three different weight percentages of (0.5, 1, and 1.5) zirconia nanoparticles are utilized for the preparation of biomimetic nanocomposite scaffolds (CSZ) employing 4 wt% of CS by a solvent casting technique. Physico-chemical and thermal behavior of the prepared nanoparticles and their CSZ scaffolds are comprehensively characterized. Bioactivity of the prepared zirconia nanoparticles and CSZ scaffolds are explored in terms of in vitro biocompatibility, protein absorption in simulated body fluid (SBF), and phosphate buffered saline (PBS). Agar disc diffusion method is employed to identify the antibacterial property against Staphylococcus aureus and Escherichia coli. In vitro cytotoxicity of zirconia nanoparticles and CSZ scaffolds is identified against human urothelial carcinoma (UC6) and osteosarcoma (MG-63) cells. These studies explore that zirconia nanoparticles are suitable for biomedical applications while it is interacted with chitosan and sodium alginate (CS) due to their promising biocompatibility. Biomimetically obtained chitosan/sodium alginate scaffold contain 1 wt% zirconia nanoparticles show higher biocompatibility amenable for tissue engineering applications.

Efficacy of Graphene-Based Nanocomposite Gels as a Promising Wound Healing Biomaterial.

The development of biocompatible nanocomposite hydrogels with effective wound healing/microbicidal properties is needed to bring out their distinguished characteristics in clinical applications. The positive interaction between graphene oxide/reduced graphene oxide (GO/rGO) and hydrogels and aloe vera gel represents a strong strategy for the advancement of therapeutic approaches for wound healing. In this study, the synthesis, characterization, and angiogenic properties of graphene-based nanocomposite gels have been corroborated and substantiated through several in vitro and in vivo assays. In this respect, graphene oxide was synthesized by incorporating a modified Hummer's method and ascertained by Raman spectroscopy. The obtained GO and rGO were uniformly dispersed into the aloe vera gel and hydrogel, respectively, as wound healing materials. These formulations were characterized via in vitro bio-chemical techniques and were found suitable for the appropriate cell viability, attachment, and proliferation. In addition, in vivo experiments were conducted using male Wistar rats. This revealed that the GO/rGO-based gels stimulated wound contraction and re-epithelialization compared to that of the non-treatment group. From the study, it is suggested that GO/rGO-based aloe vera gel can be recommended as a promising candidate for wound healing applications.