Synthesis of tubular g-C3N4 via a H2SO4-assisted precursor self-assembly strategy for enhanced photocatalytic degradation of organic pollutant

Abstract

Nanostructured graphitic carbon nitride (g-C3N4) has attracted enormous attention as a promising visible-light photocatalyst because of its unique physicochemical properties. However, controlling the nanostructure of g-C3N4 is challenging because the most common template methods are high-cost and high-risk intensive as well as tedious. In this work, tubular g-C3N4 is prepared in situ by annealing a melamine-cyanurate supramolecular array, which is conducted through a H2SO4-assisted precursor self-assembly strategy. The as-prepared samples are characterized by X-ray diffraction, scanning electron microscopy, Brunauer–Emmett–Teller analysis, and other photoelectrochemical measurements. Moreover, the band structure of the g-C3N4 nanotubes is investigated to elucidate the carrier separation mechanism. The result shows that the g-C3N4 nanotubes have a hollow structure (average diameter: 0.2–1.2 μm, length: 10–50 μm, and thickness: 15–20 nm) and an enhanced electronic structure. Owing to the high specific surface area of their hierarchical pores and the efficient charge separation of their 1D feature, the g-C3N4 nanotubes exhibit high photocatalytic methylene blue (MB)/tetracycline (TC) degradation rates of 0.0265 min−1 and 0.0110 min−1, which are three and seven times higher than those of Bulk g-C3N4, respectively. Therefore, this study provides a facile and effective strategy for the construction of carbon nitride nanostructures.