Dispersed conductive polymer nanoparticles on graphitic carbon nitride for enhanced solar-driven hydrogen evolution from pure water

Abstract

Developing new methods to improve the photocatalytic activity of graphitic carbon nitride (g-C₃N₄) for hydrogen (H₂) evolution has attracted intensive research interests. Here, we report that the g-C₃N₄ exhibits photocatalytic activity for H₂ evolution from pure water. And, the activity is dramatically improved by loading highly dispersed conductive polymer nanoparticles. The H₂ evolution rate increases up to 50 times for g-C₃N₄ with 1.5 wt% polypyrrole (PPy) nanoparticles on the surface. The reaction proceeding in a pure water system excludes the need for sacrificial agents. The role of the highly conductive PPy in enhancing H₂ evolution is as a surface junction to increase the number of photoinduced electrons, and to facilitate electron transfer to the interface.

Fabrication of conductive and high-dispersed Ppy@Ag/g-C3N4 composite photocatalysts for removing various pollutants in water

“…Combining the conductive polymers with g-C 3 N 4 to form organic-organic heterostructures photocatalyst, P3HT-g-C 3 N 4 , PANI-g-C 3 N 4 and g-PAN-g-C 3 N 4 has been reported for hydrogen production and MB photodegradation under visible-light and showed high photocatalytic performance [23][24][25]. Though the introduction of P3HT, PANI and g-PAN is effective to improve the photocatalytic performance, it is expensive and difficult to obtain through organic synthesis which inhibits their practical application [26,27]. Polypyrrole (PPy) is an organic semiconductor with band-gap of 2.2-2.5 eV, good environmental stability, high conductivity and interesting redox properties [28][29][30][31].…”

Modelling materials for solar fuel synthesis by artificial photosynthesis; predicting the optical, electronic and redox properties of photocatalysts

“…The most well-known of these photocatalysts are the inorganic solids [1][2][3]6], mostly oxides but also sulfides and selenides, the former including titanium dioxide [13][14][15], the quintessential photocatalyst. Perhaps less well-known, a range of supramolecular systems [16,17] and even organic polymers [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] have also been reported to act as photocatalysts. In this mini-review we will discuss computational work on modelling such photocatalysts in terms of the relevant material properties and processes, as well as what we believe to be key aspects to consider when performing such calculations.…”

“…Many photocatalysts are comprised of more than one material or phase and the exciton can dissociate on the interface between two of these phases/materials. The formation of heterostructures can be intentional, as for example in the carbon nitride-carbon nanodots [34] and carbon nitride-polypyrrole [29] systems, or an unintentional side-effect of the material's prep aration, as in for example the often used Degussa P25 titanium dioxide, which is a mixture of the anatase and rutile phases. Presence of these heterostructures can have a very significant effect on the photocatalytic activity.…”

Nanoparticles of Graphitic Carbon Nitride: Stabilization in Aqueous Solutions, Spectral and Luminescent Properties

“…1b, curve 1) there is a band at 810 cm -1 , which is the so-called fingerprint of heterocycles of the triazine and heptazine series and arises from the deformation vibrations of the N-C=N bonds in these compounds [16,17,27]. Apart from this, the spectrum contains bands at 1265, 1320, 1420, 1490, and 1570 cm -1 , characteristic of triazine, heptazine, and their derivatives [27][28][29][30], and also a band at 1620 cm -1 , which can be assigned to the deformation vibrations of adsorbed water. In the region of 3000-3500 cm -1 there is a broad composite band due to the stretching vibrations of the OH groups of adsorbed water and the remaining NH 2 and NH groups in the GCN.…”