Halloysite nanotubes@reduced graphene oxide composite for removal of dyes from water and as supercapacitors

Halloysite nanotubes (HNTs) were dispersed and loaded homogeneously onto the surface of reduced graphene oxide (rGO) sheets via an electrostatic self-assembly process. The selective modification of the outmost surface with γ-aminopropyl triethoxysilane (APTES) was performed. The outmost surface of the APTES–HNTs (APHNTs) was converted into a positively charged surface under acidic conditions due to the existence of amine-tailed short organic chains. A combination then occurred driven by the electrostatic force between the negative GO sheets and positive APHNTs. A HNTs@rGO composite (HGC) was fabricated after reduction of GO and investigated as an adsorbent and electrode material. The superior behavior of HGC for rhodamine B (RhB) removal and high performance as a supercapacitor highlight the potential applications of HGC in waste water treatment and energy storage issues.