Construction of carbon dots modified hollow g-C3N4 spheres via in situ calcination of cyanamide and glucose for highly enhanced visible light photocatalytic hydrogen evolution. (8th January 2022)

• Record Type: Journal Article
• Authors: Ding, Yuan; Lin, Zhi; Deng, Jiawei; Liu, Yingliang; Zhang, Li; Wang, Kunlun; Xu, Shengang; Cao, Shaokui
• Is Part Of: International journal of hydrogen energy. Volume 47:Number 3(2022)
• Page Start: 1568
• Page End: 1578
• Publication Date: 2022-01-08
• Subjects: g-C3N4 -- Carbon dots -- Hollow spheres -- In situ calcination -- Photocatalyst -- Hydrogen evolution; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.10.108
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: In this work, a series of carbon dots (CDs) modified hollow g-C3 N4 spheres (HCNS-Cx ) were constructed via a double in situ approach using cyanamide and glucose as precursors, respectively. As HCNS-Cx was synthesized by one-step in situ thermal polymerization of two precursors, which could make CDs and g-C3 N4 keep tight connection and increase the separation of the photogenerated electron-hole pairs. The average diameter and wall thickness of the HCNS-Cx are about 355 nm and 55 nm, respectively. Under the visible light irradiation, the H2 evolution rate (HER) of HCNS-C1.0 (2322 μmol g −1 h −1 ) was 19 times that of bulk g-C3 N4 (122 μmol g −1 h −1 ) and 1.8 times that of HCNS without CDs modification (1289 μmol g −1 h −1 ), respectively. And its apparent quantum efficiency is 17.93% at 420 nm. The specific surface area, light absorption capacity, and charge carrier mobility of HCNS-Cx could be dramatically improved due to the introduction of CDs and hollow structures of g-C3 N4 spheres, resulting in a significant improvement of photocatalytic activity. Graphical abstract: Image 1 Highlights: Carbon dots modified hollow g-C3 N4 spheres were constructed via an in situ approach. The hollow sphere structure could increase the specific surface area and light absorption capacity. CDs could decrease the recombination of electron-hole pairs significantly. HER of HCNS–C1.0 is 19 times higher than that of BCN.