Titania-supported bimetallic catalysts for photocatalytic reduction of nitrate

Highly effective photocatalytic system comprising semiconductor photocatalyst and supported bimetallic non-photocatalyst for selective reduction of nitrate to nitrogen in water

“…Among the semiconductor photocatalysts, TiO 2 has one of the highest potentials for practical applications because of its chemical stability, nontoxicity, and low cost. The photocatalytic activity of TiO 2 has been increased by modifying it with noble metals [26,29,33]. Zhang et al have reported that TiO 2 modified with a homogeneous dispersion of Ag clusters with small sizes shows extremely high activity for the photocatalytic reduction of NO 3 -in water in the presence of formic acid as a hole scavenger and that NO 3 -is selectively reduced to N 2 [29].…”

“…However, the selectivity significantly decreases from >99% to 20% when ethanol is used as a hole scavenger [29]. Gao et al have demonstrated that bimetal-modified TiO 2 , Cu-Pd/TiO 2 , which is prepared by using a conventional impregnation method, shows photocatalytic activity for the conversion of NO 3 -under UV irradiation in the presence of oxalic acid, whereas unmodified TiO 2 shows low photocatalytic activity [33]. Kominami et al have reported that NO 3 -is effectively and selectively reduced to N 2 in the presence of Cu-Pd/TiO 2 , which is prepared by using a photodeposition method, in the presence of oxalic acid as a hole scavenger under basic conditions [27].…”

“…In recent years, selective photocatalytic reduction of NO 3 -in water over noble metal modified semiconductor phototcatalysts has been reported [26][27][28][29][30][31][32][33][34]. Among the semiconductor photocatalysts, TiO 2 has one of the highest potentials for practical applications because of its chemical stability, nontoxicity, and low cost.…”

Photoelectrochemical behavior of bimetallic Cu–Ni and monometallic Cu, Ni doped TiO2 for hydrogen production

“…Cu and Ni can be considered as the appropriate dopants for TiO 2 in PEC cell because the oxides form of copper (CuO and Cu 2 O) displayed photocatalytic activity comparable to the noble metals due to their narrow bandgap energies (1.4 and 2.2 eV), negative conduction positions (À0.96 and À0.22 V) and high light absorption coefficient [24]. On the other hand, Ni as a fairly costly transition metal has been proposed for improving the photocatalytic activity of some semiconductors by improving the thermal stability and controlling the morphology of mesoporous photocatalysts [17]. In this study, a novel photoanode of bimetallic (CueNi/TiO 2 ) and monometallic doped TiO 2 (Cu/ TiO 2 and Ni/TiO 2 ) was synthesized as the photoanodes in PEC cell.…”

Assessing the environmental impact of five Pd-based catalytic technologies in removing of nitrates

“…metals [5,11], catalytic hydrogen [12], or photocatalytic reactions [13] have proved to decompose and destruct nitrate rapidly. These methods are highly efficient and may be performed at relatively low cost [14].…”