Photocatalytic Reduction of Carbon Dioxide over Self‐Assembled Carbon Nitride and Layered Double Hydroxide: The Role of Carbon Dioxide Enrichment

Abstract

A self‐assembly of carbon nitride (C3N4) and layered double hydroxide (LDH) was constructed by electrostatic interaction. The pristine nitrate‐intercalated Mg‐Al‐LDH is turned to carbonate LDH through anion exchange during the photoreduction of CO2 in aqueous solution. The carbonate anions enriched in the interlayer of LDH exhibit a remarkably high reduction efficiency to CH4 in the presence of a C3N4 photoabsorber and Pd cocatalyst.

Carbon nitride nanosheet/metal–organic framework nanocomposites with synergistic photocatalytic activities

“…The various reactions involved in the process, along with their corresponding redox potentials, are described by Equations (1) to (13). Under visible light irradiation, electrons could be excited from the valence band (VB) of CNNSs to its conduction band (CB) and holes were simultaneously generated in the VB (Equation (1)).…”

“…CN, the band gap of which is typically ca. 2.7 eV, 7 has been used to catalyse a number of reactions and particularly: water splitting, 7,10 carbon dioxide reduction [11][12][13] and degradation of contaminants in water. 14,15 Its purely organic nature and facile synthesis represent the key strengths of the material.…”

Photocatalysts with adsorption property for dye-contaminated water purification

“…The advantage of this method is that the reaction conditions are controllable and always generate highly crystallised LDH products. 34 With pure Al or Zn plates as a template, ZnAl-LDH crystallises on the substrate is a promising phase transition method to fabricate high-crystallized ZnAl-LDH. 39 In this method, a certain proportion of Zn and Al ions with hexamethylenetetramine (HMTA) as buffer were prepared and adjusted to pH 7.5 by adding ammonia into the solution.…”

“…201 However, there is limited research on the composition between LDH and g-C3N4. 166,[201][202][203][204] There is even fewer research on the composition between LDH and g-C3N4 which is used in water purification.…”

“…33 Moreover, the stacking is not only influenced by the anionic species but also influenced by the M 2+ /M 3+ ratio, the metallic composition ratio in starting brucite influences the staging phenomena of LDH. Sasaki et al 34 discussed the correlation between staging product and metallic composition ratio. They discovered that for transition metals LDH when a stoichiometric amount of iodine was used, Co 2+ 2/3Fe 2+ 1/3(OH)2 was completely transformed into a pure LDH phase with a different formula: Co 2+ 1-xFe 2+ x(OH)2 + 0.5xI2 →Co 2+ 1-xFe 3+ x(OH)2Ix.…”