Template-free synthesis and photocatalytic activity of {0 0 1}-facets exposed rhombohedral NaNbO3 microcrystals

Fast synthesis of NaNbO3 nanoparticles with high photocatalytic activity for degradation of organic dyes

“…14 It has many technological application properties, and, among them, the photocatalytic applications presented in the literature showed excellent results. 13 13,[15][16][17][18][19][20][21][22][23] Being a promising photocatalyst because it is thermodynamically stable, has high corrosion resistance, and is nontoxic. 22,24 However, studies have shown that the natural particle shape of NaNbO 3 is cubic and presents low photocatalytic activity, but in syntheses with hydrothermal conditions followed by heat treatment, it is possible to obtain the semiconductor in the form of nanowires, with high photocatalytic activity.…”

{0 0 1}-Facet-Exposed Ag4V2O7 Nanoplates: Additive-Free Hydrothermal Synthesis and Enhanced Photocatalytic Activity

“…It is worthy to note that to obtain the single-phase Ag 4 V 2 O 7 crystals with the highest c-axis orientation degree and yield of about 40%, the optimized amount and concentration of ammonia of 4 mL and 2.5 M, respectively, providing the pH of 9.5 for reaction mixture are required strictly. As illustrated in Figure 4, the band gap energy values of the random-and c-axis-oriented samples of 2.44 and 2.47 eV, respectively, were almost the same and fell in the range found for Ag 4 V 2 O 7 [19,20].…”

“…As a result, the Ta 5 + -doped rutile TiO 2 arrays were grown preferably along [1 1 0] direction, instead of along c-axis observed for undoped samples [17]. There are only a limited number of additivefree chemical synthesis procedures of faceted photocatalysts, in which other preparative parameters than additives were exploited for facet engineering so far [18,19]. Liang et al synthesized nanoparticle-aggregated cone-like ZnO mesocrystals enclosed by curved 1 0 1 1 and flat 0 0 0 1 surfaces by a water-induced precursor-hydrolysis process in a water/ organic solvent system [18].…”

“…The results showed that the volume ratio between organic solvent and water played a key role for tailoring the final crystal shape of ZnO with controllable facets. In our recent work, by using freshly produced Nb 2 O 5 •H 2 O instead of frequently used, commercialized Nb 2 O 5 as a precursor, the c-axis-oriented and {0 0 1}-facetexposed rhombohedral NaNbO 3 plate-like microcrystals with enhanced photocatalytic activity were resulted [19]. The formation of the faceted rhombohedral NaNbO 3 platelike microcrystals synthesized by a template-free hydrothermal method was suggested to be attributed to the difference in chemical reactivity between Nb 2 O 5 •H 2 O and other polymorphisms of Nb 2 O 5 .…”