Visible-light response hybrid aerogel and preparation method and application thereof in waste gas processing

A preparation method of silver metavanadate quantum dot/carbon nitride nanosheet composites, comprising the following steps:

• (1) using dicyandiamide as a precursor, after a first calcination and a second calcination, preparing carbon nitride nanosheets;
• (2) dispersing carbon nitride nanosheets in water and growing silver metavanadate quantum dots in situ to prepare silver metavanadate quantum dot/carbon nitride nanosheet composites,
• wherein in the step (1), the first calcination is carried out in argon gas, a first heating rate is 5° C./min during the first calcination, and a first calcination time is 4 h, a first calcination temperature is 550° C.;
• and the second calcination is carried out in air, a second calcination rate is 5° C./min, a second calcination time is 2 h, and a second calcination temperature is 550° C.

A method for exhaust gas treatment, comprising the following steps:

• (1) using dicyandiamide as a precursor, after a first calcination and a second calcination, preparing carbon nitride nanosheets;
• (2) dispersing carbon nitride nanosheets in water and growing silver metavanadate quantum dots in situ to prepare silver metavanadate quantum dot/carbon nitride nanosheet composites;
• (3) carrying out hydrothermal reaction of silver metavanadate quantum dot/carbon nitride nanosheet composite with graphene oxide, followed by freeze-drying to prepare silver metavanadate quantum dots/carbon nitride nanosheets/graphene hybrid aerogel, which is a visible-light response hybrid aerogel;
• (4) passing the exhaust gas through the visible-light response hybrid aerogel, illuminating to complete the treatment of the exhaust gas,
• wherein in the step (1), the first calcination is carried out in argon gas, a first heating rate is 5° C./min during the first calcination, and a first calcination time is 4 h, a first calcination temperature is 550° C.;
• and the second calcination is carried out in air, a second calcination rate is 5° C./min, a second calcination time is 2 h, and a second calcination temperature is 550° C.