Robust Binding between Carbon Nitride Nanosheets and a Binuclear Ruthenium(II) Complex Enabling Durable, Selective CO₂ Reduction under Visible Light in Aqueous Solution

Abstract

Carbon nitride nanosheets (NS-C N ) were found to undergo robust binding with a binuclear ruthenium(II) complex (RuRu') even in basic aqueous solution. A hybrid material consisting of NS-C N (further modified with nanoparticulate Ag) and RuRu' promoted the photocatalytic reduction of CO to formate in aqueous media, in conjunction with high selectivity (approximately 98 %) and a good turnover number (>2000 with respect to the loaded Ru complex). These represent the highest values yet reported for a powder-based photocatalytic system during CO reduction under visible light in an aqueous environment. We also assessed the desorption of RuRu' from the Ag/C N surface, a factor that can contribute to a loss of activity. It was determined that desorption is not induced by salt additives, pH changes, or photoirradiation, which partly explains the high photocatalytic performance of this material.

Sugarcane juice derived carbon dot–graphitic carbon nitride composites for bisphenol A degradation under sunlight irradiation

“…It is well-known that the organic semiconductor g-C 3 N 4 possesses visible light harvesting properties due to its narrow band gap energy (≈2.7 eV) [15]. Thus g-C 3 N 4 has emerged as a promising polymeric semiconductor for photocatalytic reduction of carbon dioxide (CO 2 ) [16–20], hydrogen evolution [21–25], oxidation of NO [26–27], and degradation of pollutants [28–30]. However, the photocatalytic performance of bulk g-C 3 N 4 remains unsatisfactory because of the fast recombination rate of electron pairs and narrower light absorption range over the entire solar spectrum.…”

Artificial Photosynthesis with Polymeric Carbon Nitride: When Meeting Metal Nanoparticles, Single Atoms, and Molecular Complexes

“…The ruthenium complex (X = PO 3 H 2 ) held the best performance of converting CO 2 into HCOOH with TON >1000 and QY reaching 5.7% at 400 nm. Later, the same group built a PCN‐based Z‐scheme system with the Ru(II) binuclear complex comprising of both photosensitizing and catalytic units, possessing high selectivity for CO 2 reduction toward HCOOH (87−99%) and producing a TON of ≈33 000 for 48 h with a nanoparticulate Ag modifier . This study indicated that the bifunctional binuclear metal molecular complexes could be much more efficient than the mononuclear metal complexes in photocatalysis.…”

Surface modification of layered perovskite Sr2TiO4 for improved CO2 photoreduction with H2O to CH4

“…In order to improve the optical properties of TiO 2 , it has been combined with various metals to form hybridized composites such as Ag/TiO 2 15 , Pt/TiO 2 16 , Ru/TiO 2 17 , Pd/TiO 2 18 , Ni/TiO 2 19 , Cu/TiO 2 20 , TiO 2 /Cu-TiO 2 21 , CeO 2 -TiO 2 22 , MgO-TiO 2 23 , NiO-In 2 O 3 /TiO 2 24 , CuS x -TiO 2 25 , NiS-TiO 2 26 , In 2 O 3 /TiO 2 27 , TiO 2 /Fe-TiO 2 28 and multi-walled carbon nanotube (MWCNT)@TiO 2 29 in an attempt to reduce the band gap or suppress recombination of photogenerated charge carriers. Also, catalysts having a combination of an organic and metal material such as g-C 3 N 4 30 , Ni 12 P 5 /g-C 3 N 4 31 , Au cluster-NP/C 3 N 4 32 , AgX/g-C 3 N 4 (X = Cl and Br) 33 , RuRu′/Ag/NS-C 3 N 4 34–37 and Co-ZIF 38–41 are being developed.…”