Gaining a deeper understanding of enzyme catalysis is of great practical and fundamental importance. Over the years it has become clear that despite advances made in experimental mutational studies, a quantitative understanding of enzyme catalysis will not be possible without the use of computer modeling approaches. While we believe that electrostatic preorganization is by far the most important catalytic factor, convincing the wider scientific community of this may require the demonstration of effective rational enzyme design. Here we make the point that the main current advances in enzyme design are basically advances in directed evolution and that computer aided enzyme design must involve approaches that can reproduce catalysis in well-defined test cases. Such an approach is provided by the empirical valence bond method.

First use of a surfactant-free SnS nanorods synthesized by a solvothermal method in supercapacitor applications having high specific capacitance.

We report the studies on composite gel polymer electrolytes (GPEs) comprising 0.5 M solution of sodium trifluoromethane sulfonate (Na-triflate or NaTf) in ionic liquid 1-ethyl 3-methyl imidazolium trifluoromethane sulfonate (EMITf) entrapped in poly (vinylidinefluoride-cohexafluoropropylene) (PVdF-HFP) dispersed with passive filler Al 2 O 3 and active filler NaAlO 2 particles. The freestanding films of the composite GPEs, prepared from solution-cast method, offer optimum ionic conductivity at room temperature (6.3-6.8 × 10 − 3 S cm − 1 and 5.5-6.5 × 10 −3 S cm −1 for Al 2 O 3 -and NaAlO 2 -dispersed GPEs, respectively), with sufficient electrochemical stability and excellent thermal stability up to 340°C. As observed from XRD and SEM, the composites are of predominantly amorphous and porous character, which support the high ionic conduction. The sodium ion transport number has been found to be ∼0.27 for Al 2 O 3 -dispersed GPE and 0.42 for NaAlO 2 -dispersed GPE, which indicates the predominant role of passive and active fillers, Al 2 O 3 and NaAlO 2 , respectively. The dispersion of NaAlO 2 enhances the sodium ion conductivity in composite GPE substantially. The overall ionic conductivity is same as in the case of Al 2 O 3 dispersion. The performance characteristics of GPE, particularly, dispersed with active filler NaAlO 2 show its potential applicability as electrolyte/ separator in sodium batteries.

The development of low cost supercapacitor cells with unique capacitive properties is essential for many domestic and industrial purposes. Here we report the first ever application of SnS-reduced graphene oxide (SnS/RGO) layered nanocomposite as a superior electrode material for symmetric aqueous hybrid supercapacitors. We synthesized SnS/RGO nanocomposite comprised of nanosheets of SnS and graphene oxide via a one-pot hydrothermal approach. in situ as-synthesized SnS/RGO is devised for the first time to give high specific capacitance 500 Fg, energy density 16.67 Wh kg and power density 488 W kg. The cell retains 95% charge/discharge cycle stability up to 1000 cycles. In-short, the SnS/RGO nanosheet composite presented is a novel and advanced material for application in high stability moderate value hybrid supercapacitors. All the currently available surveys in literature state the potential applicability of SnS as the anode material for reversible lithium/sodium ion batteries (LIBs/NIBs) but there is a lack of equivalent studies on electrochemical capacitors. We filled up this knowledge gap by the use of the same material in a cost-effective, highly active hybrid supercapacitor application by utilizing its pseudocapacitance property combined with the layered capacitance property of graphene sheets.

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