Abstract
Noble metals (Pt, Au) decorated Sr-incorporated g-C
3
N
4
photocatalysts are fabricated via facile calcination and photo-deposition methods.
The optical absorption and charge separation properties of the photocatalysts are remarkably improved and the Pt/0.15Sr-CN photocatalyst exhibited excellent activity for CO
2
conversion.
A quantum efficiency of 2.92% is predicted for CO
2
reduction over the Pt/0.15Sr-CN photocatalyst at 420 nm wavelength, which is accredited to the improved optical absorption and enhanced charge separation via Sr-incorporation and the surface plasmon resonance effect of noble metal nanoparticles.
The photocatalytic performance of g-C
3
N
4
for CO
2
conversion is still inadequate by several shortfalls including the instability, insufficient solar light absorption and rapid charge carrier’s recombination rate. To solve these problems, herein, noble metals (Pt and Au) decorated Sr-incorporated g-C
3
N
4
photocatalysts are fabricated via the simple calcination and photo-deposition methods. The Sr-incorporation remarkably reduced the g-C
3
N
4
band gap from 2.7 to 2.54 eV, as evidenced by the UV–visible absorption spectra and the density functional theory results. The CO
2
conversion performance of the catalysts was evaluated under visible light irradiation. The Pt/0.15Sr-CN sample produced 48.55 and 74.54 µmol h
−1
g
−1
of CH
4
and CO, respectively. These amounts are far greater than that produced by the Au/0.15Sr-CN, 0.15Sr-CN, and CN samples. A high quantum efficiency of 2.92% is predicted for the Pt/0.15Sr-CN sample. Further, the stability of the photocatalyst is confirmed via the photocatalytic recyclable test. The improved CO
2
conversion performance of the catalyst is accredited to the promoted light absorption and remarkably enhanced charge separation via the Sr-incorporated mid gap states and the localized surface plasmon resonance effect induced by noble metal nanoparticles. This work will provide a new approach for promoting the catalytic efficiency of g-C
3
N
4
for efficient solar fuel production.