Crafting Mussel‐Inspired Metal Nanoparticle‐Decorated Ultrathin Graphitic Carbon Nitride for the Degradation of Chemical Pollutants and Production of Chemical Resources

Abstract

The development of efficient photocatalysts for the degradation of organic pollutants and production of hydrogen peroxide (H2O2) is an attractive two‐in‐one strategy to address environmental remediation concerns and chemical resource demands. Graphitic carbon nitride (g‐C3N4) possesses unique electronic and optical properties. However, bulk g‐C3N4 suffers from inefficient sunlight absorption and low carrier mobility. Once exfoliated, ultrathin nanosheets of g‐C3N4 attain much intriguing photocatalytic activity. Herein, a mussel‐inspired strategy is developed to yield silver‐decorated ultrathin g‐C3N4 nanosheets (Ag@U‐g‐C3N4‐NS). The optimum Ag@U‐g‐C3N4‐NS photocatalyst exhibits enhanced electrochemical properties and excellent performance for the degradation of organic pollutants. Due to the photoformed valence band holes and selective two‐electron reduction of O2 by the conduction band electrons, it also renders an efficient, economic, and green route to light‐driven H2O2 production with an initial rate of 0.75 × 10−6 m min−1. The improved photocatalytic performance is primarily attributed to the large specific surface area of the U‐g‐C3N4‐NS layer, the surface plasmon resonance effect induced by Ag nanoparticles, and the cooperative electronic capture properties between Ag and U‐g‐C3N4‐NS. Consequently, this unique photocatalyst possesses the extended absorption region, which effectively suppresses the recombination of electron–hole pairs and facilitates the transfer of electrons to participate in photocatalytic reactions.

Production of Hydrogen Peroxide by Photocatalytic Processes

“…They ield of H 2 O 2 with the fabricated Au/g-C 3 N 4 photocatalyst reached 1320 mmol L À1 after irradiation with light for 240 min;t his yield is 2.3-times higher than that of the pristine g-C 3 N 4 .Inthe other study,Zuo et al [60b] observed asimilar improvement in the production of H 2 O 2 production with aA u/C 3 N 4 photocatalyst. Theauthors also compared in this study the effect of different co-catalysts (Au, Ag, Pd, and Pt) on g-C 3 N 4 for the production of H 2 O 2 .T he results showed that g-C 3 N 4 loaded with Au NPs exhibited the best performance for the production of H 2 O 2 .T he enhanced H 2 O 2 production was attributed to the efficient separation of charge carriers between the finely dispersed Au NPs and g-C 3 N 4 .M ore recently,C ai et al [61] fabricated silver-decorated ultrathin g-C 3 N 4 nanosheets (Ag@U-g-C 3 N 4 -NS;F igure 10 a,b). The Ag@U-g-C 3 N 4 -NS exhibited am uch stronger absorption of light in the 200-2000 nm range (Figure 10 c), as aresult of the localized surface plasmon resonance (SPR) of the loaded Ag NPs.I na ddition, the Ag NPs also effectively separated the photogenerated carriers by forming aSchottky barrier, while the large specific surface area of the ultrathin nanosheet construction could facilitate the transfer of electrons to participate in photocatalytic reactions,t hereby leading to the improved photocatalytic performance (Figure 10 d).…”

Sulfur Loading and Speciation Control the Hydrophobicity, Electron Transfer, Reactivity, and Selectivity of Sulfidized Nanoscale Zerovalent Iron

“…Highly redox active materials are an important tool for the degradation of refractory organic water and soil contaminants. [ 1–7 ] Nanoscale zero valent (NZVI) has been used for in situ groundwater remediation for more than two decades. [ 8–12 ] NZVI is a strong reductant that readily dechlorinates chlorinated solvents and antibiotics, and reduces and immobilizes heavy metals and radionuclides.…”

Nanostructured Carbon Nitrides for CO2 Capture and Conversion

“…Carbon nitrides (CNs) are exclusive class of materials that have gained significant importance in various areas of energy storage and conversion (batteries, supercapacitors, and fuel cells), energy production (photoreduction of CO 2 , photocatalytic water splitting), catalysis, optoelectronics, gas capture, environmental remediation, and sensing in the past few years. These application perspectives could be attributed to their outstanding physico‐chemical properties such as basicity, low density, good chemical/thermal stability, and tunable electronic parameters .…”