One‐pot self‐assembly and photoreduction synthesis of silver nanoparticle‐decorated reduced graphene oxide/MIL‐125(Ti) photocatalyst with improved visible light photocatalytic activity

In recent years, tremendous research efforts have been made towards developing metal–organic framework (MOF)‐based composites for photocatalytic applications. In this work, bipyramid‐like MIL‐125(Ti) frustum enwrapped with reduced graphene oxide (rGO) and dispersed silver nanoparticles (Ag NPs) was fabricated using an efficient one‐pot self‐assembly and photoreduction strategy. The as‐obtained materials were characterized using field emission scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, nitrogen adsorption–desorption isotherms, and X‐ray photoelectron, ultraviolet–visible diffuse reflectance and photoluminescence spectroscopies. It is found that the as‐prepared Ag/rGO/MIL‐125(Ti) ternary hybrids have large surface area, microporous structure, enhanced visible light absorption and prolonged lifetime of charge carriers. Compared with pure MIL‐125(Ti) and its binary counterparts, the ternary composite exhibits more efficient photocatalytic performance for Rhodamine B (RhB) degradation from water under visible light irradiation. The photodegradation rate of RhB on Ag/rGO/MIL‐125(Ti) is 0.0644 min −1 , which is 1.62 times higher than that of the pure MIL‐125(Ti). The improved photocatalytic performance is ascribed to the indirect dye photosensitization, the Ag NP localized surface plasmon resonance, the Ti 3+ –Ti 4+ intervalence electron transfer and the synergistic effect among MIL‐125(Ti), Ag NPs and rGO. Ag NPs serve as an efficient ‘electron reservoir’ and rGO as an electron transporter and collector. Therefore, this work provides a new pathway into the design of MOF‐based composites for application in environmental and energy fields. Copyright © 2016 John Wiley & Sons, Ltd.