Tuning Band Gap in Fe-Doped g-C₃N₄by Zn for Enhanced Fenton-Like Catalytic Performance

Abstract

Multiple oxidation states of first-row transition-metal cations were always doped in g-C3N4 to enhance the catalytic activity by the synergistic action between the cations in the Fenton-like reaction. It remains a challenge for the synergistic mechanism when the stable electronic centrifugation (3d 10) of Zn2+ was used. In this work, Zn2+ was facilely introduced in Fe-doped g-C3N4 (named xFe/yZn-CN). Compared with Fe-CN, the rate constant of the tetracycline hydrochloride (TC) degradation increased from 0.0505 to 0.0662 min–1 for 4Fe/1Zn-CN. The catalytic performance was more outstanding than those of similar catalysts reported. The catalytic mechanism was proposed. With the introduction of Zn2+ in 4Fe/1Zn-CN, the atomic percent of Fe (Fe2+ and Fe3+) and the molar ratio of Fe2+ to Fe3+ at the catalyst’s surface increased, where Fe2+ and Fe3+ were the active sites for adsorption and degradation. In addition, the band gap of 4Fe/1Zn-CN decreased, leading to enhanced electron transfer and conversion from Fe3+ to Fe2+. These changes resulted in the excellent catalytic performance of 4Fe/1Zn-CN. Radicals •OH, •O2 –, and 1O2 formed in the reaction and took different actions under various pH values. 4Fe/1Zn-CN exhibited excellent stability after five cycles under the same conditions. These results may give a strategy for synthesizing Fenton-like catalysts.

Enhancement of the peroxidase-like activity of hollow spherical FexNi1−xS2/SC nanozymes

“…We proposed that Ni 2+ might accelerate the conversion of Fe 3+ to Fe 2+ as eqn (5), which is the key step to enhance the catalytic activity for ˙OH formation in the Fenton reaction. 32 A similar result was reported. 19 An internal electron transfer from Ni 2+ to Fe 3+ in an FeNi–MOF accelerated the Fe 3+ /Fe 2+ redox cycle.…”

Singlet Oxygen Formation Mechanism for the H2O2-Based Fenton-like Reaction Catalyzed by the Carbon Nitride Homojunction

“…33−35 Compared to CN and HCN, the peaks at 810 cm −1 and in the range of 3000−3600 cm −1 are significantly weaker, but the peak at 2168 cm −1 corresponded to the stretching vibration of C�N is enhanced for HCCN. 36 Compared to CN, the peaks of HCN within the range of 1100−1800 cm −1 were slightly changed, probably due to the increase in crystallinity, while the peaks of HCCN were significantly changed due to the fact that the addition of NH 4 Cl and NaSCN in the fabrication of HCCN affects or disrupts the structure of g-C 3 N 4 . These results indicate that− NH 2 at the edge of g-C 3 N 4 was replaced by C�N in HCCN, confirming that cyano groups were introduced into HCCN.…”

Enhanced Visible-Light H2O2 Production over Pt/g-C3N4 Schottky Junction Photocatalyst

“…Recently, photocatalytic H 2 O 2 production has attracted increasing attention since it only utilizes solar energy and O 2 + water as raw materials; therefore, it is cost-efficient and eco-friendly. , The extensively investigated photocatalysts, include TiO 2 , − g-C 3 N 4 (CN), , etc. g-C 3 N 4 as a star visible-light photocatalyst has been widely investigated and applied for photocatalytic H 2 evolution, CO 2 reduction, , pollutant degradation, − and H 2 O 2 production ,, due to its suitable band gap ( E g = 2.7 eV), easy synthesis, nontoxicity, low cost, and excellent chemical stability. However, the low specific surface area, fast recombination of photogenerated carriers, and poor surface electron migration rate of single g-C 3 N 4 severely limit its applicability .…”