Construction of Highly Efficient Graphitic Carbon Nitride Photocatalyst Based on Hard-template Approach Toward Degradation of Various Organic Pollutants

Abstract

Annually different kinds of organic pollutants such as dyes, antibiotics, and phenol groups enter into the environment from various industries including pharmacies, food industries, and shrimp farming. These organic pollutants cause serious detrimental effects for humans, animals, and the whole ecosystem. Photocatalytic degradation of organic pollutants is recognized as a highly efficient method in the remediation of wastewater from these organic compounds. The energy source of photocatalysis is solar light which is an abundant, non-toxic, safe, and cheap energy resource. Among various photocatalysts, graphitic carbon nitride (g-C3N4), a two-dimensional conjugated polymer, has drawn broad attraction because of its several advantages including low in cost, metal-free, visible light active, and high stability. However, engineering a highly efficient g-C3N4 is challenging and still in progress. One way to improve the activity of g-C3N4 is to control its morphology, size and hence enhance its active reaction sites. In this study hard-templating approach was implemented in three different methods. Three different morphologies of graphitic carbon nitride were successfully synthesized with the aim of enhancing porosity, specific surface area, optical properties and generally, increasing photoactivity of graphitic carbon nitride as the photocatalyst. By using silica nanoclusters, mesoporous graphitic carbon nitride was fabricated which had high capability toward degradation of rhodamine B and tetracycline. By utilizing silica microspheres, hierarchical inverse opal graphitic carbon nitride was constructed with enhanced photoactivity in the degradation of rhodamine B and methylene blue. Finally, by combining supramolecular self-assembly approach and using silica as the hard-template, a novel morphology of washer-ring-like g-C3N4 was achieved, with high ability in the degradation of bisphenol a.