A convenient method to prepare a novel alkali metal sodium doped carbon nitride photocatalyst with a tunable band structure

Abstract

A novel alkali metal sodium doped carbon nitride photocatalyst with a tunable band gap was prepared using dicyandiamide monomer and sodium hydrate as precursors. X-ray diffraction (XRD), N 2 adsorption, UV-vis spectroscopy, scanning electron microscopy (SEM), photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS) were used to characterize the prepared catalysts. The CB and VB potentials of graphitic carbon nitride could be tuned by controlling the sodium concentration. In addition, sodium doping inhibited the crystal growth of graphitic carbon nitride, enhanced the surface area and increased the separation rate of photogenerated electrons and holes. The visible-light-driven Rhodamine B (RhB) photodegradation and mineralization performances were significantly improved after sodium doping.The possible influence mechanism of sodium concentration on the photocatalytic performance is proposed.

Hydrothermally Induced Oxygen Doping of Graphitic Carbon Nitride with a Highly Ordered Architecture and Enhanced Photocatalytic Activity

“…Research has shown that doping with metal and non‐metal atoms, such as C, N, O, S, P, I, K, Na, Fe, and Cu, also plays a vital role in promoting the photocatalytic activity of g‐C 3 N 4 . Usually, a dopant energy level is be induced between the energy gap of g‐C 3 N 4 after substitution of C and N with heteroatoms, and this broadens the light‐responsive range and causes higher light efficiency as well as better electrical conductivity.…”

“…Research has shown that doping with metal and non-metal atoms, such as C, N, O, S, P, I, K, Na, Fe, and Cu, also plays a vital role in promoting the photocatalytic activity of g-C 3 N 4 . [24][25][26][27][28][29][30][31][32][33] Usually,adopant energy level is be induced between the energy gap of g-C 3 N 4 after substitution of Ca nd N with heteroatoms,a nd this broadens the light-responsive range and causes higher light efficiency as well as bettere lectrical conductivity.F or instance, ac alcination-refluxing method was reported for the synthesis of Mn-doped g-C 3 N 4 for the highly efficient photocatalyticd egradation of organic dyes and As an amorphous or semicrystalline material, graphitic carbon nitride (g-C 3 N 4 )d isplays poor photocatalytic activity owing to rapid recombination of the photogenerated chargec arriers, which is mainly caused by ah igh density of defects in the graphitic structure. In this work, ap orous O-doped g-C 3 N 4 (P-CNO) nanosheet with ah ighly ordered architecture is fabricated by introducing an ovel hydrothermal treatment to the precursor before the final thermal condensation.…”

Advances in Magnetically Separable Photocatalysts: Smart, Recyclable Materials for Water Pollution Mitigation

“…Efficient utilisation of visible light would enable the exploitation of sunlight as a source of energy, which consists of about 40% visible light. Generally, strategies such as doping the semiconductor with metal ions (alkali, alkaline earth, noble, rare earth, and transition metals) [43][44][45][46][47], non-metal ions (oxygen, sulphur, nitrogen, phosphorus, halogens, carbon, and boron) [48][49][50][51], codoping/multidoping (metal + metal, non-metal + metal, non-metal + non-metal) [52][53][54][55], coupling semiconductors with carbon nanomaterials (reduce graphene oxide (RGO), graphene oxide (GO), multiwalled carbon nanotubes (MWCNTs), single-walled carbon nanotubes (SWCNTs), carbon nanospheres (CNS), fullerenes, etc.) [56][57][58][59], sensitisation (dye, polymer and surface complex sensitisation) [60][61][62], and coupling two or more semiconductors [63][64][65] have been extensively investigated for improving the photocatalytic activity of various semiconductors.…”

Enhancement of catalytic activity and oxidative ability for graphitic carbon nitride

“…Li + , Na + , K + and among other alkali-metal ions could be incorporated into the g-C3N4 framework, causing spatial charge carrier distribution to be induced in various intercalated areas. [43,124,198] Zhang et al reported an original Na + co-doping with CNx photo-catalyst with an adjustable gap in-between bands was made with dicyandiamide monomer and NaOH as precursors [200].…”