G-C3N4 crystal phase/amorphous phase homojunction as well as preparation method and application thereof

[0033] 1.1 Heat 10 g of melamine to 600 °C at a heating rate of 2 °C / min and keep it warm for 2 hours to obtain a block carbon nitride precursor.

[0034] 1.2. Grind the bulk carbon nitride precursor in the above step 1.1 until it is powdered, take 2 g and disperse it in 5 ml deionized water, and process it ultrasonically for 1 h.

[0035] 1.3. Transfer the suspension in step 1.2 to a petri dish, and freeze-dry (i.e., vacuum freeze-dry) under the conditions of a vacuum degree of less than 20Pa and a freezing temperature of less than -20°C to obtain a light yellow powder.

[0036] 1.4. Heat the light yellow powder obtained in the above step 1.3 to 650°C at a heating rate of 60°C / min under the protection of argon gas, and then raise it to 700°C at a heating rate of 0.5°C / min and keep it warm for 2 hours. Afterwards, it is naturally cooled with the furnace to obtain the final carbon nitride product.

[0037] figure 1 with figure 2 It is the HRTEM diagram of the final produ

[0040] According to the method for embodiment 1, prepare crystalline phase / amorphous homogeneous junction carbon nitride (also referred to as C 3 N 4 homogeneous junction, the same below), the difference is: replace melamine with dicyandiamide, and at the same time ensure that 2 g of block carbon nitride can be obtained. The resulting homojunction carbon nitride morphology and figure 2 Similarly, it is a crystalline phase and an amorphous homogeneous junction structure. The size of carbon nitride nanosheets is 300-500 nm and the thickness is 5-30 nm. Calculated crystal phase C 3 N 4 with amorphous phase C 3 N 4 The area ratio between them is 1:4.

[0042] Crystal phase / amorphous homogeneous junction carbon nitride was prepared according to the method of Example 1, except that melamine was replaced by urea, and at the same time, it was ensured that 2 g of block carbon nitride could be obtained. The resulting homojunction carbon nitride morphology and figure 2 Similarly, it is a crystalline phase and an amorphous homogeneous junction structure. The size of carbon nitride nanosheets is 300-500 nm and the thickness is 5-30 nm. Calculated crystal phase C 3 N 4 with amorphous phase C 3 N 4 The area ratio between them is 1:4.