One-Pot Synthesis of TiO2/Hectorite Composite and Its Photocatalytic Degradation of Methylene Blue

Abstract

TiO2/hectorite composite photocatalysts with different molar ratios of lithium, magnesium, and silicon were synthesized by a one-pot hydrothermal method. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), N2 adsorption-desorption isotherms, and ultraviolet-visible diffuse reflectance spectra (UV-Vis DRS). When the molar ratio of lithium, magnesium, and silicon was 1.32:5.34:8 (TH-2), the composite showed the highest UV photocatalytic degradation of methylene blue (MB). The apparent rate constant of TH-2 was 0.04361 min−1, which was about 3.12 times that of EVONIK Degussa commercial TiO2 of AEROXIDE P25. The improvement of photocatalytic efficiency of the composite was mainly due to its high specific surface area, light trapping ability, and effective separation of electrons (e−) and holes (h+). At the same time, the F element of hectorite is beneficial to the formation of Ti3+ in TiO2, thus enhancing the photocatalytic activity. After five cycles, the removal rate of MB with TH-2 still reached 87.9%, indicating its excellent reusability.

Graphene oxide-supported highly porous TiO2 nanoleaflets for the ultrafast adsorption and photochemical decomposition of 2,4,6-trinitrotolune in water

“…33 The weak peaks of 2 θ appear at 32.0°, which may be attributed to the residual starting materials and some intermediate products. 34…”

Fabrication of 2D/1D Bi2WO6/halloysite nanotubes photocatalyst towards water purification: a support effect on in situ construction and electron–hole separation

“…It has been reported that loading nanoscale photocatalysts onto natural mineral support can inhibit the aggregation, enhance the adsorption capacity and promote photogenerated electron-hole pair separation for hybrid photocatalysts, subsequently improving the dispersion of powdery nanocatalysts and accelerating the degradation rate of organic pollutants [20,21]. Thus, natural minerals have become ideal choices of support materials, such as kaolinite [22], hectorite [23], saponite [24], imogolite [25], and illite [26]. Halloysite nanotubes (HNTs)are silicate mineral [27], which has aluminol (Al-OH) groups on the internal surface and Si-OH on the external surface [28,29].…”

Light-Assisted Catalysis in Water and Indoor Air Cleaning: Challenges and Perspectives

“…The study revealed that pure titania exhibited the highest activity in the photocatalytic degradation of Rose Bengal dye under UV light, along with a superior photocurrent response, compared to the incorporated hematite counterparts. Additionally, Yang et al [11] proposed utilizing TiO 2 /hectorite composites with varying molar ratios of lithium, magnesium, and silicon as photocatalysts for the photodegradation of methylene blue (MB) under UV light irradiation. Under optimized conditions (molar ratio of Li/Mg/Si = 1.32/5.34/8), the highest removal rate of MB dye (97.8%) was revealed, while reusability tests after five runs showed only a slight decrease in the photocatalytic activity.…”