Phosphorus-Doped Carbon Nitride Solid: Enhanced Electrical Conductivity and Photocurrent Generation

Abstract

As a new kind of polymeric semiconductors, graphitic carbon nitride (g-C(3)N(4)) and its incompletely condensed precursors are stable up to 550 degrees C in air and have shown promising photovoltaic applications. However, for practical applications, their efficiency, limited e.g. by band gap absorption, needs further improvement. Here we report a "structural doping" strategy, in which phosphorus heteroatoms were doped into g-C(3)N(4) via carbon sites by polycondensation of the mixture of the carbon nitride precursors and phosphorus source (specifically from 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid). Most of the structural features of g-C(3)N(4) were well retained after doping, but electronic features had been seriously altered, which provided not only a much better electrical (dark) conductivity up to 4 orders of magnitude but also an improvement in photocurrent generation by a factor of up to 5. In addition to being active layers in solar cells, such phosphorus-containing scaffolds and materials are also interesting for polymeric batteries as well as for catalysis and as catalytic supports.

In Situ Formation of Heterojunctions in Modified Graphitic Carbon Nitride: Synthesis and Noble Metal Free Photocatalysis

“…9 C 3 N 4 materials demonstrate high activity in many energy-related fields: as catalyst in heterogeneous catalysis and as metal-free photocatalysts and electrocatalysts in watersplitting reactions, 10,11 in the degradation of pollutants, 12 is strongly dependent on its morphology, size, surface area, defects, and energy states along with its electronic properties (band gap, exciton lifetime etc.). In the last year, many modifications of the common synthesis were developed, including the introduction of new heteroatoms (sulfur, phosphor) 13 into the C 3 N 4 structure, in order to manipulate its electronic, optical and catalytic properties. However, despite great progress in C 3 N 4 synthesis, the traditional solid-state synthesis of C 3 N 4 results in disorganized texture, with small grain size and surface defects, which leads to low catalytic activity.…”

Can environmental pharmaceuticals be photocatalytically degraded and completely mineralized in water using g-C3N4/TiO2 under visible light irradiation?—Implications of persistent toxic intermediates

“…This unique property and its electric conductivity make it promising for potential applications and theoretical predictions [19][20][21]. Wang et al first used g-C 3 N 4 as a photocatalyst to successfully produce hydrogen [21], and since then, research has explored H 2 evolution and organics degradation [22,23].…”

A Review of Carbon-Composited Materials as Air-Electrode Bifunctional Electrocatalysts for Metal–Air Batteries

“…However, the ORR activity of g-CN itself is not satisfactory because of its poor electrical conductivity [160,161] despite nitrogen atoms in g-CN being able to increase the electropositivity of adjacent carbon atoms. Based on this, Fu et al [162] combined carbon with porous graphitic g-CN through a template-free synthesis route to obtain g-CN/C composite catalysts for ORR in MABs.…”