Upconversion-Agent Induced Improvement of g-C₃N₄ Photocatalyst under Visible Light

Abstract

Herein, we report the use of upconversion agents to modify graphite carbon nitride (g-C3N4) by direct thermal condensation of a mixture of ErCl3·6H2O and the supramolecular precursor cyanuric acid-melamine. We show the enhancement of g-C3N4 photoactivity after Er(3+) doping by monitoring the photodegradation of Rhodamine B dye under visible light. The contribution of the upconversion agent is demonstrated by measurements using only a red laser. The Er(3+) doping alters both the electronic and the chemical properties of g-C3N4. The Er(3+) doping reduces emission intensity and lifetime, indicating the formation of new, nonradiative deactivation pathways, probably involving charge-transfer processes.

A facile fabrication of plasmonic g-C 3 N 4 /Ag 2 WO 4 /Ag ternary heterojunction visible-light photocatalyst

“…S2 shows the PL spectra of the pure g-C 3 N 4 and g-C 3 N 4 / Ag 2 WO 4 /Ag materials excited by 325 nm. The main emission peak was centred at 461 nm for the pure g-C 3 N 4 sample, which was similar to the former reports [74]. For g-C 3 N 4 /Ag 2 WO 4 /Ag hybrids, the position of the emission peak in the PL spectrum was slightly blue shift to that of the pure g-C 3 N 4 , but the emission intensity significantly decreased, which indicated that the g-C 3 N 4 /Ag 2 WO 4 / Ag hybrids had much lower recombination rate of photo-generated charge carriers.…”

Toward Efficient Carbon Nitride Photoelectrochemical Cells: Understanding Charge Transfer Processes

“…For efficient PEC the electrons should be further injected into the electron acceptor layer (path 2) while the holes are expected to Photoelectrochemical cells (PECs) are a promising technology for the production of renewable energy by converting the sun light into electrical and chemical energy. In particular, it has been widely studied as a photocatalyst and electrocatalyst for water splitting and oxygen reduction reactions, [8][9][10][11][12][13] degradation of pollutants, [14] and in the field of heterogeneous catalysis. In a typical PEC, the photoanode is composed of a light harvester attached to a wide band gap semiconductor (i.e., TiO 2 , ZnO) that serves as electrons acceptor layer while the holes are transferred to the counter electrode through the electrolyte solution.…”

Reduced graphene oxide supported titanium dioxide nanomaterials for the photocatalysis with long cycling life

“…For example, transition metal doping TiO 2 is effective to improve the Page 6 of 27 A c c e p t e d M a n u s c r i p t photocatalytic activity by decreasing the charge carrier recombination rates [12,13]; and other various non-metal-doped TiO 2 have been widely studied for the visible light photocatalytic activities [11,15,[21][22][23]. These composite TiO 2 catalysts can be used as not only an efficient photocatalyst for highly selective oxidation, but also as a multifunctional component designed to promote wider spectrum absorption and separation of electrons and holes, as well as to stabilize photolysis semiconductors [20][21][22]. Among these designs and developments, carbon materials attracted more attention because they could both improve vastly the visible light response and photocatalytic activity [8,10,20].…”