Fabricating carbon quantum dots of graphitic carbon nitride vis ultrasonic exfoliation for highly efficient H(2)O(2) production

A promising and sustainable approach for producing hydrogen peroxide is the two-electron oxygen reduction reaction (2e(–) ORR), which uses very stable graphitic carbon nitride (g-C(3)N(4)). However, the catalytic performance of pristine g-C(3)N(4) is still far from satisfactory. Here, we demonstrate for the first time the controlled fabrication of carbon quantum dots (CQDs)-modified graphitic carbon nitride carbon (g-C(3)N(4)/CQDs-X) by ultrasonic stripping for efficient 2e(–) ORR electrocatalysis. HRTEM, UV–vis, EPR and EIS analyses are in good consistent which prove the in-situ generation of CQDs. The effect of sonication time on the physical properties and ORR activity of g-C(3)N(4) is discussed for the first time. The g-C(3)N(4)/CQDs-12 catalyst shows a selectivity of up to 95% at a potential of 0.35 V vs. RHE, which is much higher than that of the original g-C(3)N(4) catalyst (88%). Additionally, the H(2)O(2) yield is up to 1466.6 mmol g(−1) in 12 h, which is twice as high as the original g-C(3)N(4) catalyst. It is discovered that the addition of CQDs through ultrasonic improves the g-C(3)N(4) catalyst's electrical conductivity and electron transfer capability in addition to its high specific surface area and distinctive porous structure, speeding up the reaction rate. This research offers a green method for enhancing g-C(3)N(4) activity.