The fabrication of TiO2 supported on slag-made calcium silicate as low-cost photocatalyst with high adsorption ability for the degradation of dye pollutants in water

Abstract

In this work, a composite photocatalyst of TiO 2 supported on the slag-made calcium silicate (TiO 2 /SCS) was synthesized by employing a facile mixing process and using blast furnace slag as a low-cost and abundant precursor of SCS. The characterization results revealed that the open framework structure of SCS was covered by well-dispersed TiO 2 nanoparticle aggregates, indicating the close combination of titania and calcium silicate in the TiO 2 /SCS photocatalyst. Higher specific surface areas could be obtained for TiO 2 /PCS and TiO 2 /SCS composites, indicating their better adsorption capabilities than that of bare TiO 2. The degradation of methylene blue (MB) by TiO 2 , TiO 2 /PCS and TiO 2 /SCS composites with different weight percentages of titania was carried out under UV-light irradiation to systematically investigate their photocatalytic activities, and the TiO 2 content of 60 wt% (TiO 2-60/SCS) was found to be the best one to achieve the maximum rate of MB degradation, which may be due to the high specific surface area and good adsorption capacity of the composite photocatalysts. The degradation of methyl violet (MV) and methyl orange (MO) dyes indicated that the obtained photocatalysts can effectively adsorb cationic molecules (MB and MV) but have little absorption toward negatively charged molecules (MO), which play a key role in the subsequent photocatalytic degradation of dye pollutants.

Metallurgical Wastes Employed as Catalysts and Photocatalysts for Water Treatment: A Review

“…Shi et al [76] produced composite materials in which commercial nanocrystalline titania was supported on a blast furnace slag rich in Ca and Si (40.09% CaO, 34.58% SiO 2 , 14.78% Al 2 O 3 , 5.29% MgO, 1.53% Fe 2 O 3 , 0.78% TiO 2 , 0.27% MnO) by means of hydrolysis and thermal treatments. They synthesized a high-purity reference support material from CaO and SiO 2 similar to the slag.…”

The effect of graphitized carbon on the adsorption and photocatalytic degradation of methylene blue over TiO2/C composites

“…17,18 Thus, the combination of some adsorbents and TiO 2 nanoparticles has attracted much attention for enhancing photocatalytic activity in the degradation of organic contaminants. [19][20][21][22][23][24][25] TiO 2 composites obtained by adding a co-adsorbent, doping, or depositing on other material are helpful for solving these problems. Supporting the TiO 2 nanoparticles on adsorbents such as activated carbon, 19 clay minerals 21,22 and calcium silicate 23 is not only benecial for improving the efficiency of photocatalysis, but also favors the separation and recovery of these catalysts from aqueous solution.…”

“…[19][20][21][22][23][24][25] TiO 2 composites obtained by adding a co-adsorbent, doping, or depositing on other material are helpful for solving these problems. Supporting the TiO 2 nanoparticles on adsorbents such as activated carbon, 19 clay minerals 21,22 and calcium silicate 23 is not only benecial for improving the efficiency of photocatalysis, but also favors the separation and recovery of these catalysts from aqueous solution. These adsorbents usually have some excellent physicochemical properties such as high surface area, porous structure, large adsorption capacity, fast adsorption kinetics, good chemical and thermal stability, and low cost.…”

Removal of methylene blue from aqueous solution by electrophoretically deposited titania‐halloysite nanotubes coatings

“…[35][36][37][38][39][40] The high adsorption capability of adsorbent phase and high photocatalytic activity of titania are exploited simultaneously by this method. Several adsorbents like activated carbon, [37][38][39][40] silica, 36,[41][42][43][44] graphene, 45 graphene oxide, 35,46 and calcium silicate 47 have been used to enhance the photocatalytic activity of titania. Clay minerals are relatively cheap and have high specific surface area encouraging their usage as the adsorbent for pollutant removal.…”