Niobium pentoxide ultra-thin nanosheets: A photocatalytic degradation and recyclable surface-enhanced Raman scattering substrate

Although the traditional SERS metal substrates have high sensitivity, their unrepeatable and ecological environment unfriendly performance greatly limits their applications. Therefore, it is necessary to explore multi-functional SERS substrates with recyclability, photocatalytic degradation, and ultra-sensitive detection ability. Herein, the Nb2O5 ultra-thin nanosheets were successfully synthesized by a simple hydrothermal method. Based on the coupled resonance effect, the SERS sensitivity of Nb2O5 substrates was optimized by the Mo doping process. The SERS enhanced factor EF of Mo-Nb2O5-MV at 1617 cm−1 with the irradiation laser of 532 nm is determined to 2.09 × 107 and the corresponding substrate possesses a low detection limit of 10−8 M, which can parallel the noble metal SERS substrates without “hot spots”. The enhanced Raman signals of MV on Mo-Nb2O5 substrates are mainly originated from photo-induced charge transfer resonance between molecules and semiconductor clusters. It is noticeable that Mo-Nb2O5 ultra-thin nanosheets substrates not only exhibit excellent SERS sensitivity and uniformity but also have recyclability, stability and rapidly photocatalytic degradation ability of dye molecules in visible-light, which expend the application of semiconductor SERS substrates in the detection and treatment of pollutants.