A dual-functional integrated Ni5P4/g-C3N4 S-scheme heterojunction for high performance synchronous photocatalytic hydrogen evolution and multi-contaminant removal with a waste-to-energy conversion Articles uri icon

publication date

  • November 2022

start page

  • 1

end page

  • 16

issue

  • 120147

volume

  • 366

International Standard Serial Number (ISSN)

  • 0167-7322

Electronic International Standard Serial Number (EISSN)

  • 1873-3166

abstract

  • With a goal of waste-to-energy conversion, herein we report synchronous hydrogen evolution and pollutant degradation via photocatalysis utilizing novel Ni5P4/g-C3N4 S-scheme (Step scheme) heterojunction. The 25 %Ni5P4/g-C3N4 (25NP/CN) sample generates 40.1 mmol g-1h-1hydrogen evolution and 94.4 % carbamazepine degradation simultaneously under visible light and anaerobic conditions. Furthermore, the hydrogen evolution with carbamazepine, bisphenol A, sulfamethoxazole and rhodamine B is manifolds higher than in water. From The in-situ XPS results confirm the S-scheme transfer between Ni5P4 and g-C3N4. The presence of Ni0@Ni5P4 where strong covalent interactions between Ni0 and Ni-P single layers on Ni5-P4 not only enhanced the visible absorption, charge transfer but also leads to hydrogen formation by H+ transfer via a cyclic intermediate in a co-ordinate complex of degradation intermediates with Ni. This route is in addition to obvious e-/H+. The CBZ degradation and hydrogen evolution in aerobic/oxic conditions was also studied and 25NP/CN performs well under this atmosphere, inferring that oxidised intermediates act as electron donors and maintains the H2 evolution in longer run too. The photogenerated holes directly oxidized the pollutant in addition to radical dotOH radicals in anoxic medium and separated/accumulated electrons leads to hydrogen evolution. The scavenging experiments reveal that photogenerated holes directly oxidized the pollutant in addition to radical dotOH radicals in anoxic medium and separated/accumulated high potential electrons (via S-scheme transfer) leads to hydrogen evolution. The clean energy production and pollutant mineralization are synchronously achieved. Henceforth, a waste-to-energy route is proposed by coupling photocatalytic hydrogen evolution to environmental restoration.

subjects

  • Materials science and engineering
  • Renewable Energies

keywords

  • s-scheme; hydrogen evolution; water treatment; photocatalytic; ni5p4/g-c3n4