The Defect Engineering Design of Cocn/L-Cds/Ni2p for Promoting Hydrogen Energy Generation from Seawater Coupling with Photoreforming of Plastics

Abstract

The use of photoreforming to treat plastics and degrade plastics to small molecular organic matter is an emerging approach to solve white pollution in the ocean and produce new energy. Structurally defective g-C3N4 (COCN) is compounded by adding ascorbic acid during the synthesis of graphitic carbon nitride (g-C3N4). L-cysteine is added to compose L-CdS. By constructing a heterojunction, we synthesize the ternary composite COCN/L-CdS/Ni2P. The hydrogen production rate of COCN/L-CdS/Ni2P reaches 29.11 mmol/g/h at 5 h, which is 7.52 times and 727.7 times of L-CdS and COCN, respectively. From the stability tests, which can be seen that COCN/L-CdS/Ni2P is more stable in seawater than in deionized water. This indicates that COCN/L-CdS/Ni2P is suitable for using seawater as a hydrogen source. During the production of hydrogen, polylactic acid (PLA) is degraded to pyruvate. This study demonstrates that COCN/L-CdS/Ni2P can not only photoreformate plastics in seawater into small molecular organics, but also efficiently produce H2 using seawater as a hydrogen source. This has a significant role to treat plastic pollution in seawater and product clean energy.

Keywords: COCN/L-CdS/Ni2P, photoreforming, waste plastics, Seawater