Enhanced electrochemical hydrogen storage properties of Ti49Zr26Ni25 quasicrystal alloy by doping with CO2-activated porous graphene

Ti49Zr26Ni25 quasicrystal alloy was fabricated via mechanical alloying and subsequent annealing. In order to enhance the electrocatalytic activity and conductivity of Ti49Zr26Ni25 , the porous graphene (PoRGO) material was synthesized by a facile CO2 activation treatment of reduced graphene oxide (RGO). The composites of Ti49Zr26Ni25 doping with different amount of PoRGO were manufactured through ball milling. During the electrochemical hydrogen storage test, the porous Ti49Zr26Ni25 + PoRGO exhibited higher discharge capacity than Ti49Zr26Ni25 + CRGO and conventional Ti49Zr26Ni25 alloy. Moreover, the additive amount of PoRGO had great influence on the electrochemical properties of Ti49Zr26Ni25. Eventually, 5 wt% PoRGO modified Ti49Zr26Ni25 alloy electrode achieved a highest discharge capacity of 270 mAh/g. The large specific surface area and distinctive porous structure of porous graphene could offer more electrochemical active sites and facilitate the hydrogen diffusion. In the meantime, the cycling stability, high-rate dischargeability (HRD) and kinetic properties of Ti49Zr26Ni25 were also improved after PoRGO loading. Consequently, porous graphene can be potential used as the dopant for the modification of hydrogen storage alloys.

Automated summary

Ti49Zr26Ni25 quasicrystal alloy was synthesized through mechanical alloying and annealing, and the electrocatalytic activity and conductivity were enhanced by doping with porous graphene (PoRGO) synthesized from reduced graphene oxide (RGO) through CO2 activation treatment. The Ti49Zr26Ni25 composites with different amount of PoRGO were prepared by ball milling. The porous Ti49Zr26Ni25 + PoRGO exhibited higher discharge capacity compared to Ti49Zr26Ni25 + CRGO and conventional Ti49Zr26Ni25 alloy in electrochemical hydrogen storage test. The amount of PoRGO dopant had significant influence on the electrochemical properties of Ti49Zr26Ni25. The Ti49Zr26Ni25 alloy electrode modified with 5 wt% PoRGO achieved the highest discharge capacity of 270 mAh/g. The large specific surface area and distinctive porous structure of porous graphene provided more electrochemical active sites and facilitated hydrogen diffusion. Furthermore, PoRGO loading improved the cycling stability, high-rate dischargeability (HRD) and kinetic properties of Ti49Zr26Ni25. Porous graphene has potential as a dopant for the modification of hydrogen storage alloys.