Graphene paper shows a great promise for the electrical energy storage. However, the high stability, purity and specific surface area have become stringent requirements for supercapacitor applications. Finding methods to tackle these problems is rather challenging. Here, we develop a facile method to prepare porous graphene papers with a thickness 0.5 mm by a thermal shock to the layer-structure graphene paper self-assembled on Cu foil under nitrogen flowing. The as-prepared porous graphene paper exhibits a large specific capacitance of 100 F g^(-1)at the scan rate of 100 m V s^(-1)with high stability and purity without any residual chemical reagents, showing a promising potential for supercapacitor applications. The high electrochemical properties are mainly attributed to the high-specific area and the improved conductivity of the porous graphene paper performed by the multieffect of reducing, cleaving and expanding to the layer-structure graphene paper by high-energy thermal heating during the thermal shock process. This work paves a pathway to the facile preparation of porous graphene paper for supercapacitor applications.
Graphitic carbon nitride(g-C3N4,CN)has attracted increasing interests in the field of photocatalysis due to its high visible-light-response.However,its photocatalytic activity is still lower for degradation of refractory contaminants such as Cr(Ⅵ)and Rhodamine B(RhB)etc.Herein,we report a facile method to synthesize a novel sulfur(S)-doped CN/reduced graphene oxide(rGO)porous nanosheet(S-CN/rGO PNs)via a supramolecular self-assembling followed by a solvothermal treatment.The as-prepared porous SCN/rGO PNs are stable with high specific surface area^188.5 m2 g-1 and exhibit a significantly enhanced photocatalytic activity of^17-fold and 15-fold higher than that of bulk CN for the degradation of RhB and Cr(Ⅵ)under visible light irradiation,respectively.Typically,50 mL of 15 mg/mL RhB can be degraded within 20 min by 10 mg S-CN/rGO PNs.The mechanism can be explained by the synergistic effect of S doping and porous structure which can effectively reduce the band gap of CN and increase the specific surface area to promote the separation and transfer of photo-generated charge carriers.The results have provided a new way to significantly enhance the photocatalytic activity of g-C3N4 for degradation of refractory contaminants.
The Au nanoparticles decorated graphene(AuNPs@Gr)/nickel foam(Gr/NiF) nanocomposite(AuNPs@Gr/NiF) was prepared by chemical vapor deposition followed by electrophoretic deposition of AuNPs on Gr/NiF. The morphology, microstructure and sensing performance of the as-prepared AuNPs@Gr/NiF nanocomposite were characterized and measured, respectively by scanning electron microscope, transmission electron microscope, ultraviolet visible spectroscopy and chemical workstation. The asprepared AuNPs@Gr/NiF nanocomposite was used as the electrode to construct a chemical sensor for the detection of hydrogen peroxide(H_2O_2). The results showed that the AuNPs distributed homogenously and stably on the surface of Gr/NiF. The chemical sensor exhibits a sensitive and selective performance to the detection of H_2O_2.
Developing environmentally friendly methods to produce hydrogen peroxide(H_(2)O_(2))has received increasing attention.Photocatalysis has been proved to be a sustainable technology for H_(2)O_(2)production.Herein,the novel non-metal elements(B,P,and S)doped g-C_(3)N_(4)tubes(B-CNT,P-CNT,and S-CNT)photocatalysts were obtained via a hydrothermal synthesis followed by thermal polymerization.By adjusting the precursor,the yield of g-C_(3)N_(4)tubes(CNT)materials has been greatly improved.The as-prepared B-CNT,P-CNT,and S-CNT photocatalysts show an enhanced photocatalytic H_(2)O_(2)production with the formation rate constants values of 42.31μM min^(-1),24.95μM min^(-1),and 24.22μM min^(-1),respectively,which is higher than that of bulk CN(16.40μM min^(-1)).The doped B,P,S elements significantly enhanced the photocatalytic activity by adjusting their electronic structures and promoting the separation of electronhole carriers.The results have shown great potential for the practical application of CNT photocatalysts.
