▎ 摘　　要

NOVELTY - Composite photoelectrode, where the titanium dioxide composite photoelectrode is made of graphite phase carbon nitride and graphene supported on the surface of a titanium dioxide nanotube array photoelectrode, and the outermost layer of the titanium dioxide composite photoelectrode is graphene. USE - Composite photoelectrode. ADVANTAGE - The composite photoelectrode greatly improve the photoelectric conversion capacity of the photoelectrode. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing a composite photoelectrode, which comprises: (A) using a titanium sheet as an anode and a platinum sheet as a cathode, a mixed solution of NaF and Na2SO4 is used as an electrolyte, and the solution is placed in a water bath at 15-30 degrees C, and the oxidation voltage is 15-25V, and after oxidation for 1-4 hours, rinsing with deionized water, and using a drum; and drying with an air dryer to obtain a titanium dioxide nanotube array photoelectrode; (B) placing the carbon nitride powder in ultrapure water for 5-10 hours to prepare a carbon nitride solution, and the coating carbon nitride solution on a titanium dioxide nanotube array photoelectrode; and repeating 3-5 times, drying in an oven at 100 degrees C for 30min, and then annealing in a muffle furnace at 300-800 degrees C for 1-3h to obtain a graphite phase carbon nitride-doped titanium dioxide nanotube array photoelectrode; and (C) subjecting the graphite oxide to ultrasonic stripping in water for 1-3 hours to obtain a graphene oxide dispersion; using the graphene dispersion as an electrolyte, and using the annealed graphite phase carbon nitride-doped titanium dioxide nanotube array photoelectrode as the cathode, and the platinum shee as the cathode; and depositing the anode at a voltage of 1-10V for 1-10min to obtain a composite photoelectrode.