No abstract

Ni2P2O7-based composites grown on conductive substrate can efficiently promote the electrical transport during the electrochemical reactions in supercapacitors. However, Ni2P2O7 nanoarrays are easily peeled off from the substrate upon repeated electrochemical reaction. Herein, Ni2P2O7 nanoarrays grown on Ni foam with surficially decorated C3N4 thin nanosheets are achieved by a hydrothermal and in situ calcination strategy. The decorated C3N4 nanosheet network on the surface fully covers both Ni2P2O7 and Ni foam and efficiently prevents Ni2P2O7 nanoarrays from peeling off during the charge and discharge cycles. The optimized composites exhibit high pseudocapacitance and greatly enhanced cycling stability. The assembled asymmetric supercapacitor shows favorable specific capacitance and stability as energy storage devices. Such a strategy for fabricating C3N4-modified Ni2P2O7 nanoarrays is feasible and efficient, and can be therefore extended for constructing other electrodes with high capacitance and excellent stability.

In this study, aluminium chloride modified schwertmannite was biosynthesized using Acidithiobacillus ferrooxidans. Heavy metals can be efficiently removed by the modified biosynthetic schwertmannite.

No abstract

β-cyclodextrin modified Schwertmannite has been successfully biosynthesized by Acidithiobacillus ferrooxidans in this study. Three main parts in this experiment are as follows: characterisation, adsorption measurements and mechanisms exploration. The stability of micro-sphere structure was reduced with β-cyclodextrin modification, while the functional groups was enhanced by β-cyclodextrin. In addition, the adsorption capabilities of Schwertmannite, formed in oversaturated β-cyclodextrin, were improved by 20.66 % for Cu(II) and 14.82 % for Cr(VI) respectively. However, the improvement of Cu(II) was associated with decreasing adsorption rates while that of Cr(VI) was companied with increasing rates. Both metal adsorptions can be roughly regarded as two adsorption phases: surface adsorption and the migration of metal ion in channels inside Schwertmannite. In binary metal solutions with high concentration, modified Schwertmannite materials showed distinct affinity to Cr(VI) instead of Cu(II). In terms of mechanisms, Cu(II) adsorption depended on the H + exchange and Cr(VI) relied on the ligand exchange, such as SO 4 2-.

No abstract

No abstract