The invention discloses a semi-
metal material, namely a Te 
nanowire / 
graphene hydrogel composite material as well as a preparation method and application thereof. The preparation method comprises the following steps: adding 
ammonium hydroxide and a 
reducing agent, namely a hydrazine 
hydrate solution, into a water solution of 
sodium tellurate and 
polyvinylpyrrolidone, performing uniform mixing, performing a 
hydrothermal synthesis reaction, performing cooling to 
room temperature, separating a 
reaction product so as to obtain precipitate, washing the precipitate to be neutral, performing 
drying and 
grinding so as to obtain Te nanowires, adding a 
graphene oxide suspension, performing uniform mixing, performing a 
hydrothermal synthesis reaction, removing excessive 
graphene oxide and Te nanowireswhich are not tightly compounded, and performing 
freeze drying, so as to obtain the 
composite material. The Te 
nanowire / graphene 
hydrogel composite material disclosed by the invention is simple in preparation method, has 
photocatalysis sterilization and photo-thermal conversion performance, thermocatalytic sterilization can be promoted through a photo-thermal synergetic function, the inactivationratio is 70-100%, no chemical 
reagent is additionally used, and the problem of secondary 
pollution of a byproduct of a conventional sterilization technique can be effectively solved.