Hydrothermal synthesis of oxygen functionalized S–P codoped g-C₃N₄ nanorods with outstanding visible light activity under anoxic conditions

Abstract

Extending the application of photocatalytic oxidation technology to the anoxic removal of organic pollutants that exist under some oxygen-free conditions is attractive but challenging. In this study, oxygen functionalized S-P codoped g-C3N4 nanorods with outstanding visible light activity under anoxic conditions are synthesized using a hydrothermal post-treatment. S and P codoping inhibits the crystal growth of graphitic carbon nitride, enhances the SBET, decreases the band gap energy, and increases the separation efficiency of photogenerated electrons and holes, which increases the anoxic photocatalytic RhB degradation constant by approximately 6.5 times. Oxygen functionalization not only increases the adsorption ability of graphitic carbon nitride but also captures the photogenerated electrons to produce photogenerated holes for RhB degradation under anoxic conditions, leading to a doubling of the RhB degradation constant. This study provides new insight into the design and fabrication of anoxic photocatalysts.

Two‐Dimensional GaX/SnS2 (X = S, Se) van der Waals Heterostructures for Photovoltaic Application: Heteroatom Doping Strategy to Boost Power Conversion Efficiency

“…Numerous methods have been adopted to modify the physical properties of 2D materials and their heterostructures. It is demonstrated that heteroatom doping can significantly change the band structure of heterostructures . Doped Cu(In, Ga)Se 2 solar cells have higher V oc compared to pure Cu(In, Ga)Se 2 and show a high conversion efficiency of 20.8% .…”

g-C3N4-Based Nanomaterials for Visible Light-Driven Photocatalysis

“…g-C 3 N 4 doping is a common strategy to broaden spectral utilization and band alignment to drive separate photogenerated charge carriers. Doping by metals such as Cu and Fe [224][225][226], non-metals such as B, C, O, or S [224,[227][228][229][230][231], and co-doping [232][233][234] have all been employed for environmental depollution applications. For example, S and O co-doped g-C 3 N 4 prepared by melamine polymerization and subsequent H 2 O 2 activation prior to trithiocyanuric acid functionalization (Figure 21a) enhanced the photocatalytic degradation of RhB (Figure 21b) 6-fold relative to the parent g-C 3 N 4 nanosheet [235].…”

Heteroatom‐Doped Carbonaceous Photocatalysts for Solar Fuel Production and Environmental Remediation

“…[296] For another example, the P, S-dual-doped g-C 3 N 4 (P-SN)a nd O,P,S-multidoped g-C 3 N 4 (P-SN (t)) were prepared by the co-polymerizationo ft hiourea and (NH 4 ) 2 HPO 4 ,a nd the hydrothermalt reatment at 150 8Cf or different times, respectively. [297] From Figure 35 a-c, SN features irregular particles composed of g-C 3 N 4 layers, P-SN features al ayered structure with ad ecreasing size compared to SN owing to a inhibiting effect of P-doping on crystal growth. The hydrothermalp rocess of P-SN for preparing P-SN (t) with an increase in hydrothermal time from 2t o1 4h leads to as elf-assembly process from nanoparticles to nanorods with ag radually decreasing S BET from 18.6 to 6.9 m 2 g À1 .F rom Figure 35 c, P-SN (6 h) features ah ybrid morphologies composed of nanopartciels and nanorods.…”

“…The P,O‐codoping presents a synergism for improving optical, electrochemical, and textural properties and for tuning the morphology characteristics of g‐C 3 N 4 based photocatalysts . For another example, the P,S‐dual‐doped g‐C 3 N 4 (P‐SN) and O,P,S‐multidoped g‐C 3 N 4 (P‐SN ( t )) were prepared by the co‐polymerization of thiourea and (NH 4 ) 2 HPO 4 , and the hydrothermal treatment at 150 °C for different times, respectively . From Figure a–c, SN features irregular particles composed of g‐C 3 N 4 layers, P‐SN features a layered structure with a decreasing size compared to SN owing to a inhibiting effect of P‐doping on crystal growth.…”

“…It was found that the P‐SN (2 h) with 7.4 wt % O content exhibits 2 times higher degradation rate than P‐SN without oxygen functionalization, ascribed to the promoted RhB adsorption, accelerated charge mobility, and improved recombination inhibition of photogenerated charge carriers through the capture of photoexcited electrons by oxygen‐containing functional groups. The further prolonging hydrothermal time from 6 to 10 to 14 h leads to a decrease in RhB degradation rate, and therefore, the 6 h of hydrothermal treatment is appropriate . Unfortunately, the reason for this decrease in photocatalysis hasn't addressed tet.…”