Constructing Pd-N interactions in Pd/g-C3N4 to improve the charge dynamics for efficient photocatalytic hydrogen evolution

Abstract

The formation of chemical bonds between metal ions and their supports is an effective strategy to achieve good catalytic activity. However, both the synthesis of active metal species on a support and control of their coordination environment are still challenging. Here, we show the use of an organic compound to produce tubular carbon nitride (TCN) as a support for Pd nanoparticles (NPs), creating a composite material (NP-Pd-TCN). It was found that Pd ions preferentially bind with the electron-rich N atoms of TCN, leading to strong metal-support interactions that benefit charge transfer from g-C 3 N 4 to Pd. X-ray absorption spectroscopy further revealed that the metal-support interactions resulted in the formation of Pd-N bonds, which are responsible for the improvement in the charge dynamics as evidenced by the results from various techniques including photoluminescence (PL) spectroscopy, photocurrent measurements, and electrochemical impedance spectroscopy (EIS). Owing to the good dynamical properties, NP-Pd-TCN was used for photocatalytic hydrogen evolution under visible-light irradiation (λ > 420 nm) and an excellent evolution rate of ~ 381 μmol•h −1 (0.02 g of the photocatalyst) was attained. This work aims to promote a strategy to synthesize efficient photocatalysts for hydrogen production by controllably introducing metal nanoparticles on a support and in the meantime forming chemical bonds to achieve intimate metal-support contact.

Graphitic carbon nitride-based nanostructures as emergent catalysts for carbon monoxide (CO) oxidation

“…163 This study paves the way for the utilization of SMSIs at low temperature for the enhancement of the catalytic activities of metal nanoparticles or single atoms supported on g-C 3 N 4 . Recently, a few studies highlighted the utilization of SMSIs in the enhancement of the catalytic activity of various metals/metal oxides like Au/TiO 2 , 164 M/Fe 2 O 4 (M = Mn, Ni, Cu, Co), 165 Ti 3 AlC 2 /TiO 2 , 166 and Co/TiO 2 166 or metal nanoparticles like Pd NPs, 167 Ru dots, 168 PdO/Zr, 169 Pt, 170 Ni–Co, 171 Ni, 172 AgPd, 173 Mn, 174 and RuP 2 175 for various catalytic reactions like CO 2 reduction, desulfurization, alcohol dry reforming, and H 2 production. However, it is still ambiguous whether the SMSI occurs in g-C 3 N 4 -based catalysts preferentially at high temperature or low temperature.…”

Recent progress of cocatalysts loaded on carbon nitride for selective photoreduction of CO2to CH4

“…[129][130][131][132][133] To achieve the stable loading of SAM cocatalysts on CN with high dispersion, diverse methods such as ligand decoration and interlaminar bridged site construction have been adopted with great improvements. 131,[134][135][136] For example, boron-oxo species can be highly dispersed on CN via a boric-acid-mediated route due to dative B-N coordination and prove to be effective mediators for anchoring transition metal (Ni, Co, Fe) atoms. 85,97 According to the report of Wang et al, Ni single atoms were anchored by boron-oxo species on g-C 3 N 4 via a facile ion exchange strategy (Fig.…”

Hollow NiP–ZnIn2S4 Heterojunction for Simultaneous Hydrogen and Pyruvic Acid Production from Lactic Acid Photoreforming

“…As a solution, a cocatalyst is usually used to lower the overpotential of hydrogen evolution reaction (HER) and prevent electron/hole pair recombination. Noble metals, such as Pt, − Pd, − Ru, − and Rh, − have proven to be highly efficient in this line, but their high costs and low availability limit their application on a large scale. Instead, transition metals, such as Co − and Ni, are cost-effective cocatalyst candidates for HER.…”