Large-Scale Preparation of g-C₃N₄ Porous Nanotubes with Enhanced Photocatalytic Activity by Using Salicylic Acid and Melamine

Abstract

Graphitic carbon nitride (g-C 3 N 4 ) nanotubes were produced by using salicylic acid-mediated melamine successfully. The obtained long g-C 3 N 4 nanotube possesses a large specific surface area and a parallel channel structure. Salicylic acid and its decomposition products present in g-C 3 N 4 influenced its formation process and inhibited the crystal growth of g-C 3 N 4 . A possible mechanism is proposed: Salicylic acid and its decomposition products facilitated the formation of g-C 3 N 4 nanosheet, and then the nanosheet coiled to form a nanotube. The tube-like structure facilitates the increase in photocatalytic activities, which are 6.7 and 2.4 times that of pristine g-C 3 N 4 in 2-propanol decomposition and CO 2 photoreduction, respectively. The enhanced photocatalytic performance was contributed by the large specific surface area, better photogenerated charge carrier transmission, and the porous nanotube structure. This research provides an easy synthetic method for the large-scale production of g-C 3 N 4 nanotubes applied in the photocatalytic field.

Graphitic carbon nitride nanotubes: a new material for emerging applications

“…142 The calcination of a mixture of melamine and salicylic acid was found to result in the formation of GCN nanosheets, which then spontaneously scrolled into 4-5 mm long tubes with a diameter of around 60 nm and porous 10 nm thick walls. 144 It was assumed that salicylic acid forms complexes with aminogroups of melamine affecting the polycondensation dynamics and precluding the formation of multi-layer stacked bulk GCN structure. As a result, predominantly few-layer sheets were formed, which tended to coil into tubes to reduce the surface energy.…”

Enhanced visible light-driven photodegradation of tetracycline by salicylic acid-modified graphitic carbon nitride and toxicity assessment

“…The photocatalytic performance of g-C 3 N 4 could be improved by copolymerizing organic acid (anthroic acid, benzoic acid, and naphthoic acid) with urea due to the fact that the benzenering in the g-C 3 N 4 framework could increase the visible light absorbance (Li et al 2018). Salicylic acid (SA) has a benzene-based structure and was proved to improve photogenerated charge carrier transmission of g-C 3 N 4 nanotubes after the copolymerization with melamine (Jia et al 2019). In previous studies, SA-modi ed g-C 3 N 4 showed excellent performance in the degradation of sulfamethazine and TC (Zhou et al 2019a).…”

A Review on Emerging Efficient and Stable Perovskite Solar Cells Based on g-C3N4 Nanostructures

“…Its outstanding physical and chemical properties and its ability to be formed in several nanostructures (nanosheets, nanotubes, etc.) [ 30 , 31 ] are the reason that g-C 3 N 4 has been widely used in various applications, such as pollutant degradation [ 32 ], CO 2 reduction [ 33 , 34 ], water splitting [ 35 , 36 ], photocatalytic applications [ 31 , 37 , 38 , 39 , 40 ], capacitors [ 41 , 42 ], and solar cells [ 43 , 44 , 45 , 46 , 47 , 48 ]. In particular, integration of graphitic carbon nitride into PSCs has drawn special attention, providing devices with potential low fabrication cost, high chemical stability, and feasibility of structure modification via surface engineering [ 49 , 50 ].…”