title: Synthesis of bacteria promoted reduced graphene oxide-nickel sulfide networks for advanced supercapacitors.
abstract: Supercapacitors with potential high power are useful and have attracted much attention recently. Graphene-based composites have been demonstrated to be promising electrode materials for supercapacitors with enhanced properties. To improve the performance of graphene-based composites further and realize their synthesis with large scale, we report a green approach to synthesize bacteria-reduced graphene oxide-nickel sulfide (BGNS) networks. By using Bacillus subtilis as spacers, we deposited reduced graphene oxide/Ni3S2 nanoparticle composites with submillimeter pores directly onto substrate by a binder-free electrostatic spray approach to form BGNS networks. Their electrochemical capacitor performance was evaluated. Compared with stacked reduced graphene oxide-nickel sulfide (GNS) prepared without the aid of bacteria, BGNS with unique nm-μm structure exhibited a higher specific capacitance of about 1424 F g(-1) at a current density of 0.75 A g(-1). About 67.5% of the capacitance was retained as the current density increased from 0.75 to 15 A g(-1). At a current density of 75 A g(-1), a specific capacitance of 406 F g(-1) could still remain. The results indicate that the reduced graphene oxide-nickel sulfide network promoted by bacteria is a promising electrode material for supercapacitors.
authors.affiliation: Key Laboratory for Micro-Nano Optoelectronic Devices of Ministry of Education, Hunan University, Changsha 410082, China.
authors.forename: Haiming
authors.initials: H
authors.lastname: Zhang
authors.forename: Xinzhi
authors.initials: X
authors.lastname: Yu
authors.forename: Di
authors.initials: D
authors.lastname: Guo
authors.forename: Baihua
authors.initials: B
authors.lastname: Qu
authors.forename: Ming
authors.initials: M
authors.lastname: Zhang
authors.forename: Qiuhong
authors.initials: Q
authors.lastname: Li
authors.forename: Taihong
authors.initials: T
authors.lastname: Wang
mesh_terms: D001412:Bacillus subtilis / Q000378:metabolism*; D025802:Electric Capacitance; D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D006108:Graphite / Q000737:chemistry*; D008422:Materials Testing; D009532:Nickel / Q000737:chemistry; D010087:Oxides / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013059:Spectrum Analysis, Raman / Q000379:methods; D055672:Static Electricity; D014961:X-Ray Diffraction
chemical_list: D010087:Oxides; D006108:Graphite; D009532:Nickel; C017558:nickel sulfide