One-spot synthesis of FeOOH/rGO composites by ferrous-ion-induced self-assembly of graphene oxides with different degrees of oxidation

In this study, graphene oxide sheets with different oxidation degrees were reduced by ferrous ion for coating FeOOH nano particles on reduced graphene oxide (rGO) matrix to synthesize FeOOH/rGO composites. The effect of the degree of oxidation on the morphology and chemical structure of FeOOH/rGO was studied using scanning electron microscopy, Raman spectroscopy, thermogravimetric analysis, and Brunauer-Emmett-Teller surface area analysis. The particle size of FeOOH crystallites was approximately 100 nm, and they were distributed uniformly on the surface and in the pores of FeOOH/rGO. FeOOH/rGO prepared with mildly oxidized graphite had fewer defects, higher specific surface area, and higher FeOOH content than FeOOH/rGO prepared with highly oxidized graphite. These features resulted in better electrochemical properties, such as larger specific capacitance and lower charge transfer resistance.

In vivo and in vitro efficient textile wastewater remediation by Aspergillus niger biosorbent

In this work, the treatment of textile wastewater by a facile and high-efficiency technology using eco-friendly Aspergillus niger as a biosorbent was investigated. We measured physical changes (weight, size) during the formation and growth of fungus pellets and the pH values that influence the adsorption performance and biosorption mechanism. Three acid anionic dyes containing Acid Orange 56, Acid Blue 40 and Methyl Blue were chosen as model dyes to investigate batch adsorption efficiency. Two adsorption models (in vivo and in vitro) were adopted to decolorize the acid dyes. The results show that fungus pellets have excellent decoloration abilities with a high adsorption efficiency of 98% for 200 mg L^-1 of acid dye. The pH value of the dye solution varied with the adsorption time and the dye removal efficiency greatly depended on the pH. The bioadsorption mechanism of nano-scale hyphae was revealed to be mainly due to electrostatic interactions caused by the pH change. Furthermore, the surface morphologies of the fungus after adsorption indicated that the dyes had been adsorbed on the surface of the fungus mycelia. Moreover, prepared 3D fungus/GO aerogels demonstrated superior dye removal abilities compared with fungus aerogels.

Cesium-doped graphene grown in situ with ultra-small TiO2 nanoparticles for high-performance lithium-ion batteries

A composite of ultra-small TiO₂ nanoparticles grown in situ on cesium-doped reduced graphene oxide with high electronic and Li⁺ conductivity.