Pyrolysis conversion of metal organic frameworks to form uniform codoped C/N-Titania photocatalyst for H2 production through simulated solar light

Abstract

In this contribution, C/N-TiO2 photocatalyst has been synthesized employing the combustion approach of NH2-MIL-125(Ti) at 400 °C in air for H2 production through simulated solar light compared with either NH2-MIL-125(Ti) or commercial P-25. TEM images show well defined shape TiO2 nanocrystalline with 10 nm particles size. The obtained C/N-TiO2 photocatalyst exhibited large surface area 1066 m2 g−1 with high pore volume ∼0.537 cm3 g−1 and pores diameter ∼1.3 nm. The yield of H2 evolution over C-N/TiO2 photocatalyst (339 H2 mmol g−1) exhibited significantly compared with NH2-MIL-125(Ti) (5.7 H2 mmol g−1) and P-25 TiO2 (144.8 H2 mmol g−1) photocatalyst. The yield of H2 evolution over C/N-doped TiO2 was boosted by 60 and 2.35 times after 6 h over NH2-MIL-125(Ti) and P-25 TiO2 photocatalyst. The H2 evolution rate of C/N-TiO2 photocatalyst reached 33.3 mmol g-1 h-1 and it is greater 2.17 and 27.5 times than P-25 TiO2 (15.3 mmol g-1 h−1) and NH2-MIL-125(Ti) (1.212 mmol g-1 h−1). The enhancement of photocatalytic efficiency over C/N-TiO2 photocatalyst was referred to its great mesoporosity, hierarchical structure and large surface area. The recycled C/N-TiO2 photocatalyst showed significant durability through five consecutive runs for 30 h illumination. The C/N-TiO2, synthesized from pyrolysis of NH2-MIL-125(Ti), is proposed as an outstanding material for H2 evolution and potential photocatalysis application under simulated solar Light.