Construction of direct Z‐scheme g‐C₃N₄/TiO₂ nanorod composites for promoting photocatalytic activity

Abstract

Direct Z‐scheme g‐C3N4/TiO2 nanorod composites were prepared for enhancing photocatalytic activity for pollutant removal. The characterization revealed that the g‐C3N4/TiO2 nanorod composite formed a close interface contact between g‐C3N4 and TiO2 nanorods, which was of benefit for the charge transfer and resulted in its high photocatalytic activity. The g‐C3N4/TiO2 nanorod composites exhibited higher photocatalytic activity for degradation of Rhodamine B (RHB) than bare g‐C3N4 and TiO2 nanorods. The high photocatalytic activity of g‐C3N4/TiO2 nanorod composites is attributed to the formation of the direct Z‐scheme system, in which the electrons from the conduction band (CB) of TiO2 combine with the holes from the valence band (VB) of C3N4 while the electrons from the CB of C3N4 and holes from the VB of TiO2 with stronger redox ability are used to reduce and oxidize pollutants. Based on the radical‐trapping experiments, the main reactive species for RHB degradation are O2− and ·OH, which are produced by photoinduced electrons and holes with high redox ability. This work provides insights into the photocatalytic mechanism of composite materials for the photocatalytic removal of organic pollutants.

Two‐step calcination synthesis of Z‐scheme α‐Fe2O3/few‐layer g‐C3N4 composite with enhanced hydrogen production and photodegradation under visible light

“…[38] The secondary calcination samples show a significant blueshift compared to the once-calcined α-Fe 2 O 3 /ML g-C 3 N 4 , possibly because the secondary calcination of g-C 3 N 4 peels off into fewer layers, resulting in a quantum confinement effect. [14,18,39] While that of various α-Fe 2 O 3 /FL g-C 3 N 4 exhibit an apparent redshift, the redshift is increasingly enhanced with the increase of α-Fe 2 O 3 content. The enhancement of the visible light absorption intensity provides a possibility of improving the photocatalytic activity of α-Fe 2 O 3 /FL g-C 3 N 4 in the visible region.…”

“…Moreover, the Z-scheme photocatalytic system with a step-wise charge-transfer pathway, which is different from the widely used solid junction, not only favors photogenerated charge separation but also maintains excellent redox capacity of the two constituent semiconductors. [16][17][18][19][20] α-Fe 2 O 3 , especially with tailored shapes, is one of the most important semiconductors and has been widely used in photosensitizers, photo-Fenton reactions, and photocatalysis because of its deep suitable VB structure and its many intrinsic shape-dependent properties. [21][22][23] Many studies have confirmed that the properties of α-Fe 2 O 3 make it a good candidate for coupling with other semiconductors to construct Z-type heterojunctions with enhanced photoactivity.…”

Pure Organic Persistent Room‐Temperature Phosphorescence at both Crystalline and Amorphous States

“…However, unlike inorganic and organometallic phosphors, [30][31][32][33][34] the fabrication of efficient pure organic RTP luminogens remains challenging, owing to the spin-forbidden intersystem crossing (ISC) process and the high susceptibility of phosphorescence to molecular motions and external quenchers. [3][4][5][7][8][9][10][11][12][13] Even though great advances have been achieved for the molecular design of pure organic RTP through incorporation of halogens, aromatic carbonyls, and heteroatoms, [7][8][9][10][11][12][13] as well as effective suppression of nonradiative processes by supramolecular interactions, [35,36] micelle stabilization, [37] absorption on solid substrate, [38] crystal-lization, [3,4,7,[15][16][17] embedding into rigid matrices, [5,23,39] chemical bonding to polymer chains, [14] etc., the development of pure organic RTP remains in its infant stage. Furthermore, persistent RTP (p-RTP) with naked eye visible emission after ceasing the excitation is even difficult to achieve, despite it has diverse promising applications in advanced OLEDs, bioimaging, encryption and anticounterfeiting.…”

“…Furthermore, persistent RTP (p-RTP) with naked eye visible emission after ceasing the excitation is even difficult to achieve, despite it has diverse promising applications in advanced OLEDs, bioimaging, encryption and anticounterfeiting. [5][6][7][8][9][10][11][12][40][41][42][43][44][45][46] So far, increasing examples have been explored in host-guest systems, [5,40] H-aggregates, [6,41,42] crystals [43][44][45][46][47][48][49][50] and even nonconventional luminogens free of aromatics, [51,52] the mechanism and rational design strategy, however, remain open questions.…”

Synergistic effect of titanium‐oxide integrated with graphitic nitride hybrid for enhanced electrochemical performance in lithium‐sulfur batteries

“…While, the (002) plane with a 0.34 nm interplanar spacing is consisted with graphite. 40,41 In more detail, the corresponding EDS element mapping images are shown in Figure 3D and reveal uniform distribution of C, N, Ti, and O in TOCN. SEM images of sulfur particles and TOCN@S composite are displayed in Figure 3E,F.…”