Rational Ionothermal Copolymerization of TCNQ with PCN Semiconductor for Enhanced Photocatalytic Full Water Splitting

Abstract

Photocatalytic full water splitting remains the perfect way to generate oxygen (O2) and hydrogen (H2) gases driven by sunlight to address the future environmental issues as well as energy demands. Owing to its exceptional properties, polymeric carbon nitride (PCN) has been one of the most widely investigated semiconductor photocatalysts. Nevertheless, blank PCN characteristically displays restrained photocatalytic performance due to high-density defects in its framework that may perhaps perform the part of the recombination midpoint for photoproduced electron–hole pairs. Therefore, to overcome this problem, a simple approach to introduce 7,7,8,8-tetracyanoquinodimethane (TCNQ) with an electron-withdrawing characteristic modifier into the pristine PCN framework by the ionothermal method to enhance its optical, conductive, and photocatalytic properties has been undertaken. Results show that such integration of TCNQ results in the delocalization of the π-conjugated structure; significant changes in its chemical electronic configuration, band gap, and surface area; and enhanced production of electrons under visible light. As a result of this facile integration, our best sample (CNU-TCNQ9.0) produced a hydrogen evolution rate (HER) of 164.6 μmol h–1 for H2 and an oxygen evolution rate (OER) of 14.8 μmol h–1 for O2, which were found to be 2.4- and 2.6-fold greater than those produced with pure carbon nitride (CNU) sample, respectively. Hence, this work provides a reasonable alternative method to synthesize and design novel CNU-TCNQ backbone photocatalyst for organic photosynthesis, CO2 reduction, hydrogen evolution, etc.

Polymeric Carbon Nitride‐Derived Photocatalysts for Water Splitting and Nitrogen Fixation

“…This was attributed to the copolymerization of BA and 2,5, 8‐triaminotri‐s‐triazine, which kept the CO group in the PCN matrix and anchored the organic groups on the PCN, thus narrowing its bandgap width and improving the light absorption range. Ashiq Hayat and co‐workers [ 109 ] introduced organic monomer 7,7,8,8‐tetracyanoquinodimethane (TCNQ) with electron‐withdrawing characteristic into the carbon nitride (CNU) framework by ion‐thermo copolymerization, thereby causing delocalization of the CNU conjugate structure, significantly changing its electronic structure, light absorption range (Figure 11c) and SSA, and finally improving its photocatalytic water splitting ability. In summary, copolymerization is a unique method for adjusting the bandgap of PCN, but it is generally not applicable to inorganic semiconductors.…”

Retracted: A concise review on the elastomeric behavior of electroactive polymer materials

“…In recent years, functional polymer composite materials are attracting the interest of researchers in more and more applications, including polymer‐based dielectric capacitors, which are used in power transmission, hybrid vehicles, high‐power weapons, radar, wind power, and microelectronics 2 . The system and other fields have broad application prospects 3–5 . For example, the converter valve is the core part of the high‐voltage direct current transmission project 4 .…”

“…The system and other fields have broad application prospects 3–5 . For example, the converter valve is the core part of the high‐voltage direct current transmission project 4 . It can convert alternating current (AC) into direct current (DC), and the dielectric capacitor occupies more than 50% of the volume of the converter valve.…”

Homogeneous iron‐doped carbon‐nitride‐based organo‐catalysts for sensational photocatalytic performance driven by visible light

“…Wastewater, mostly produced by industry is carcinogenic and harmful to human consumption and aquatic life. Adsorption, incineration, chemical and biological degradation are used to treat these toxic substances as remedial reactions 1–4 . For environmental health, sensing and biomedical applications, photoreactions seem to be a safe option.…”

“…It is also environmentally friendly, low cost and thermodynamically stable 22,26 . However, the charge carriers have a short life, hampering its efficiency as a photocatalyst 2,6,27 . But it can become an efficient catalyst, combined with another semiconductor such as g‐CN.…”