The effect of oxygen on the N2 photofixation ability over N vacancies embedded g-C3N4 prepared by dielectric barrier discharge plasma treatment

Abstract

In this work, N vacancies embedded g-C3N4 was prepared by dielectric barrier discharge plasma treatment. The plasma treatment does not change the structure, specific surface area and morphology of catalyst, but introduce nitrogen vacancies into g-C3N4. The atmosphere has a significant effect on the nitrogen photofixation performance of as-prepared catalyst using methanol as hole scavenger. Under the atmosphere of 50% O2 and 50% N2, the as-prepared N vacancies embedded g-C3N4 displays the ammonium ion production rate as high as 5.5 mg·L−1·h−1·gcat−1, which is 2.1 times higher than that under pure nitrogen atmosphere. The effect of oxygen on the N2 photofixation ability over N vacancies embedded g-C3N4 is investigated. A “two-path” ammonia production mechanism is proposed in this work.