Basic Molten Salt Route to Prepare Porous SrTiO₃ Nanocrystals for Efficient Photocatalytic Hydrogen Production

Abstract

SrTiO 3 nanocrystals with porous structures were synthesized by a basic molten salt method. TEM images confirmed that the SrTiO 3 nanocrystals possess a cellular morphology. Highresolution TEM and selected-area electron diffraction (SAED) analysis proved the existence of pores even in single crystals. Time-dependent observations indicated that the formation of pores in the SrTiO 3 nanocrystals resulted from the phase transformation of the TiO 2 precursor in the basic solvent, and the process follows the dissolution-nucleation-ag-

Porous Single‐Crystal‐Based Inorganic Semiconductor Photocatalysts for Energy Production and Environmental Remediation: Preparation, Modification, and Applications

“…Depending on the criterium employed, several different classifications are possible. In this way, the methods can be grouped according to the reaction type as solvothermal (hydrothermal),2,16,17 sol–gel synthesis,18 chemical vapor deposition (CVD),19 molten‐salt reaction,20,21 electrochemical22 and ion‐exchange methods 23,24. Moreover, based on the strategy to generate porosity, preparation procedures for PSCs can also be divided into hard‐templating,2,7,16,17,23,25–27 soft‐templating,28–35 and template‐free 22,36–41.…”

“…The aggregation‐merge process has also been used to synthesize at a relatively low temperature a SrTiO 3 PSC with shallow pits by an exothermal alkali‐dissolution reaction that provides simultaneously alkalinity and temperature for the crystallization of the amorphous precursor 18. A cellular SrTiO 3 sample was prepared by a molten‐salt method to control the material synthesis 20. Similarly, a Bi 2 WO 6 PSCs with tetragonal architecture could be also prepared by a molten‐salt method 21.…”

Cooperative assembly synthesis of mesoporous SrTiO3with enhanced photocatalytic properties

“…Recently, diverse works showed the preparation of mesoporous SrTiO 3 nanoparticles for photocatalytic applications. [11][12][13][14][15][16] Ouyang & Ye 12 presented the synthesis of mesoporous SrTiO 3 nanoparticles by hydrothermal method using silica spheres (10-20 nm) as nanotemplate. The materials showed interesting activity in photodegradation of 2-propanol to acetone.…”

Synthesis of mesoporous strontium titanate by molten salt assisted template‐free method

“…SrTiO 3 was synthesized by the molten salt method: mixed hydroxides (50 g NaOH/KOH 51.5:48.5, analytical grade) were placed in a 50‐mL Teflon vessel, covered to prevent pollution. The vessel was preheated at 205°C for 3 hours until the hydroxides were completely molten.…”

“…The traditional high‐temperature calcination method for SrTiO 3 synthesis , makes the regulation of morphology difficult. Mesoporous SrTiO 3 has been previously synthesized in NaOH/KOH molten salt bath at a very low temperature (205°C); however, poor crystallinity was obtained . Crystallinity is an important factor affecting photocatalytic activity: improved crystallinity produces enhanced photocatalytic activity.…”