Synthesis and Structure of ZnO-Decorated Graphitic Carbon Nitride (g-C3N4) with Improved Photocatalytic Activity under Visible Light

Abstract

The volume of dye production in the chemical industry is growing rapidly every year. Given the global importance of clean water resources, new wastewater treatment solutions are required. Utilizing photocatalysis by harvesting solar energy represents a facile and promising solution for removing dangerous pollutants. This study reports the possibility of increasing the photocatalytic activity of g-C3N4 by creating nanocomposites with ZnO. Exfoliated g-C3N4/ZnO nanocomposites were synthesized by heat treatment of urea and subsequent ultrasonic exfoliation of the colloidal solution by introducing zinc acetate. The uniformity of the distribution of ZnO nanoparticles is confirmed by the method of elemental mapping. The obtained X-ray diffractograms of the obtained nanocomposites show typical X-ray reflections for g-C3N4 and ZnO. It was found that the introduction of oxide into g-C3N4 leads to an increase in the specific surface area values due to the developed ZnO surface. The maximum value of the specific surface area was obtained for a sample containing 7.5% ZnO and was 75.2 m2/g. The g-C3N4/7.5% ZnO sample also demonstrated increased photocatalytic activity during the decomposition of methylene blue under the influence of visible light, which led to a twofold increase in the reaction rate compared to initial g-C3N4.

Влияние морфологических и структурных параметров тетраподов ZnO на их активность в реакции фотокаталитической деградации ципрофлоксацина

“…Диоксид титана (TiO 2 ) остается наиболее изученным и востребованным фотокатализатором [4]. В последние годы ведутся активные исследования в области разработки альтернативных фотокатализаторов, в том числе материалов на основе оксида цинка (ZnO) [5][6][7].…”

Photocatalytic Activity of Ag Nanoparticles Deposited on Thermoexfoliated g-C3N4

“…This material exhibits a bandgap of ca. 2.70 eV, is cost-effective, has good chemical stability, is easily accessible, and is environmentally friendly [5,8,9]. However, g-C 3 N 4 in bulk form has a poor specific surface area and a fast electron-hole pair recombination rate, leading to low photocatalytic performance [10].…”

New Advances into Nanostructured Oxides

“…Lastly, the approach based on C 3 N 4 growth on pre-formed ZnO shows an intermediate condition in terms of both crystallinity and optical activity under visible frequencies. Chebanenko et al [14] reported the production of ZnO-decorated graphitic carbon nitride (g-C 3 N 4 ) nanocomposites synthesized following a three-step process, namely: (i) heat treatment of urea, (ii) ultrasonic exfoliation of the colloidal solution by introducing different ratios of ZnO precursor, and (iii) final thermal treatment. The authors reported a very interesting photocatalytic system by placing g-C 3 N 4 in close contact with ZnO nanoparticles, since the formation of a heterojunction between these two components allows for the achievement of both excitation by visible light and a better charge separation with the formation of O-containing radicals.…”