Type-II CuFe₂O₄/Graphitic Carbon Nitride Heterojunctions for High-Efficiency Photocatalytic and Electrocatalytic Hydrogen Generation

Abstract

Solar water splitting has emerged as an urgent imperative as hydrogen emerges as an increasingly important form of energy storage. g-C3N4 is an ideal candidate for photocatalytic water splitting as a result of the excellent alignment of its band edges with water redox potentials. To mitigate electron–hole recombination that has limited the performance of g-C3N4, we have developed a semiconductor heterostructure of g-C3N4 with CuFe2O4 nanoparticles (NPs) as a highly efficient photocatalyst. Visible-light-driven photocatalytic properties of CuFe2O4/g-C3N4 heterostructures with different CuFe2O4 loadings have been examined with two sacrificial agents. An up to 2.5-fold enhancement in catalytic efficiency is observed for CuFe2O4/g-C3N4 heterostructures over g-C3N4 nanosheets alone with the apparent quantum yield of H2 production approaching 25%. The improved photocatalytic activity of the heterostructures suggests that introducing CuFe2O4 NPs provides more active sites and reduces electron–hole recombination. The g-C3N4/CuFe2O4 heterostructures furthermore show enhanced electrocatalytic HER activity as compared to the individual components as a result of which by making heterostructures g-C3N4 with CuFe2O4 increased the active catalytic surface for the electrocatalytic water splitting reaction. The enhanced faradaic efficiency of the prepared heterostructures makes it a potential candidate for efficient hydrogen generation. Nevertheless, the designed heterostructure materials exhibited significant photo- and electrocatalytic activity toward the HER, which demonstrates a method for methodically enhancing catalytic performance by creating heterostructures with the best energetic offsets.

Oxide based Heterostructured Photocatalysts for CO2 Reduction and Hydrogen Generation

“…[83] The synergistic effects enhance the photocatalytic activity by overcoming aforementioned disadvantages and thus, proven very efficient for hydrogen generation by utilizing oxide based heterostructured photocatalysts. [84]…”

Graphene-Based Derivatives Heterostructured Catalytic Systems for Sustainable Hydrogen Energy via Overall Water Splitting

“…Enhancing the photochemical response of photocatalysts is basically reliant on four factors that are (a) inhibiting the recombination of photo-induced electron-hole pairs, (b) tailoring the band gap of photocatalysts in the visible light region, (c) suitable catalytic support acting as a co-catalyst and (d) a higher specific surface area as it provides more adsorption sites [3,14,41,92]. To improve the photocatalytic activity, an efficient photocatalytic system should possess durable photo-induced charge carriers, fewer charge-capturing sites and a suitable band gap [93][94][95][96].…”

“…One of the most economical and efficient ways of H 2 production is overall water splitting (OWS) [41]. OWS is a chemical approach that enables H 2 evolution by breaking the water into its elemental composition, hydrogen and oxygen [42].…”

Z-Scheme CuOx/Ag/TiO2 Heterojunction as Promising Photoinduced Anticorrosion and Antifouling Integrated Coating in Seawater

“…Regarding the protection against microbial corrosion, the addition of antibacterial components to the protective paints or coatings has been commonly used to achieve antifouling and antibacterial effects [ 19 ]. Although many heavy metals and rare earth elements, such as Cu, Ag, Ce, La, etc., have a strong bactericidal effect [ 20 , 21 , 22 ], their adverse effects on the environment need to be considered [ 23 ]. It is reported that some semiconductors can be also used for photocatalytic sterilization and antifouling, which is correlated with the generation of reactive oxygen species (ROS, such as superoxide radicals •O 2 − and hydroxyl radicals •OH) under irradiation and their inhibition to the growth of bacteria [ 24 ].…”