Direct Growth of Highly Organized Crystalline Carbon Nitride from Liquid-Phase Pulsed Laser Ablation

Abstract

The novel technique of liquid-phase pulsed laser ablation has been used to obtain unique, highly ordered nanostructures of crystalline carbon nitride (C3N4) via ablation of a graphite target submerged in aqueous ammonia solution. Transmission electron microscopy (TEM) analysis shows that the morphology of the carbon nitride material changes at different length scales, depending upon the synthesis conditions. The initial ablation product comprises spherical nanoparticles of carbon nitride, which then elongate to nanorods (10 nm by ∼200 nm) with further ablation. Given sufficient concentration, the nanorods aggregate to form multilayered structures, and then ultimately larger, ordered “leaf-shaped” structures 30−50 nm by ∼200 nm in size. With even higher concentration, these leaflike structures can themselves aggregate to create interconnected networks of large micrometer scale clusters, which ultimately rearrange to micrometer-sized flowerlike structures. The various nanostructures were characterized using a number of analysis techniques, and their composition was found to be consistent with that of crystalline α- or β-phase carbon nitride. A formation mechanism for these structures is proposed that rationalizes the observed morphologies.

Crystalline carbon nitride film synthesized by ion beam assisted magnetron sputtering and thermal annealing in nitrogen gas

“…The first contribution at 398.8 eV corresponds to sp 3 CN bonding, while the second one at 400.2 eV is due to sp 2 CN bonding, other peak fitted at 399.5-399.6 eV is attributed to nitrile. Also, it should be noted that C`N bonds can also produce three peaks in this region, at 398.2, 398.1 and 400.1 eV [31][32][33]. However, these assignments have been discounted, because they are outside the experimental accuracy of the XPS.…”

Pulsed laser ablation in liquid for micro-/nanostructure generation

“…Typical examples are ZnO nanorods or spindles produced by PLA of Zn in water at elevated temperature or with the addition of LDA or CTAB [129,130], and the ZnO nanorods could assemble into three-dimensional clusters [129], Other examples include Mg(OH) 2 nanorods produced by PLA of Mg in aqueous solutions of SDS [145], and Ag 2 O pentagonal rods and bars produced by excimer laser ablation of Ag in aqueous solution of polysorbate 80 [23]. Yang et al have synthesized carbon nitride nanorods by PLA of graphite in ammonia solution, which could further aggregate into leaf-like and flower-like structures [160,203,204]. Recently, an electricalfield-assisted PLAL method was developed to synthesize GeO 2 and CuO nanospindles (Fig.…”

Flower-like porous hematite nanoarchitectures achieved by complexation–mediated oxidation–hydrolysis reaction

“…Recent successes in the chemical production of hierarchical structures composed of nanoscaled building blocks, such as nanoflakes [1][2][3][4][5], nanowires [6][7][8], nanorods [9][10][11][12], nanobelts [13][14][15], nanotubes [16], have received much attention in the light of their high specific surface area and novel optical, electronic, optoelectronic, catalytic and absorption properties. Two main approaches are generally developed to fabricate these structures.…”