A Review on Carbon Quantum Dots Modified g-C3N4-Based Photocatalysts and Potential Application in Wastewater Treatment

Abstract

Carbon quantum dots (CDs) are a fascinating class of carbon nanomaterials (less than 10 nm in size) with unique optical, electrical, and physicochemical properties. In addition to these properties, CQDs exhibit the desired advantages of aqueous stability, low toxicity, high surface area, economic feasibility, chemical inertness, and highly tunable photoluminescence behaviour. Recently, graphitic carbon nitride (g-C3N4) has appeared as one of the required stable carbon-based polymers due to its varied applications in several fields. In this regard, modification strategies have been made in the g-C3N4 semiconductor using CQDs to enhance the adsorptive and photocatalytic activity. In comparison to other semiconductor quantum dots, g-C3N4 shows strong fluorescent properties, such as wide excitation spectra, photostability, and tunable photo-luminescent emission spectra. The interaction inside this multicomponent photocatalyst further promotes the photocatalytic activity by improving charge transference, which plays a vital role in electrochemistry. Therefore, CQDs are auspicious nanomaterials in the field of photocatalysis, wastewater treatment and water adsorption treatment. This particular article featured the recent progression in the field of CDs/g-C3N4-based photocatalysts focusing on their luminescent mechanism and potential applications in wastewater treatment.

Carbon-Based Nanomaterials for Catalytic Wastewater Treatment: A Review

“…Owing to their small dimensions, ability to absorb visible light, and up-conversion photoluminescence properties, CDs exhibit electron transfer/reservoir properties, making them excellent materials when combined with another semiconductor for photocatalysis. Recently, many groups have prepared metal-free CDs/g-C 3 N 4 hybrid photocatalysts for various photocatalytic applications [ 112 , 113 ]. Li et al fabricated CQD-decorated g-C 3 N 4 by a novel strategy employed for rhodamine B (RhB) degradation under visible light irradiation [ 114 ].…”

“… ( a ) Comparison of the degradation rate constant of C-dots-modified g-C 3 N 4 ( b ) Schematic diagram showing the one-pot synthesis of C-dots-modified g-C 3 N 4 with enhanced photocatalytic activity. Reproduced with permission from Elsevier [ 113 ]. …”

Green Synthesis Photoluminescent of Carbon Dots Extracted from Black Mulberry Fruits for Photocatalytic Degradation of Pollutant

“…The application of innovative techniques for preparing such carbon dots with desired size, shape, and functionalities remains the key to the success in the theoretical chemistry fields and applied physics for nanomaterials applications and treatment of waste-water through photocatalytic degradation is very significant for the community because c-dots prepared from bluck mulberry fruits cheap, simple and available. Carbon quantum dots, ultrafine carbon nanomaterials below 5 nm, have gained a ention for their excellent mechanical, chemical, and fluorescent capabilities, photostability, and biocompatibility [22][23][24]. With straightforward, affordable preparation methods offering a distinct advantage in nanotechnology, CDs are ideal for a variety of functions and have great photostability, biological compatibility, biosensing, and low cytotoxicity [25].The study needs a carbon dot synthesis method that is dependable, inexpensive, and rapid, differentiating top-down from bo om-up approaches based on the original carbon source [26].…”

Nanostructured boron carbon nitride as a visible light-driven catalyst for efficient wastewater treatment

“…Graphene has paved the way for the advancement of layered materials like carbon nitride (C3N4) and boron nitride (BN), possessing characteristics ideal for various applications, including chemical sensors, pollutant removal, solar cells, and water splitting [7][8][9]. C3N4, possessing a graphitic nature, is a cost-effective semiconductor known for its stability against oxidation.…”