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Nejc Suban

Publications and source records attributed to Nejc Suban.

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Improvement of piezocatalytic performance of Na0.5Bi0.5TiO3 perovskite using K doping for efficient Rhodamine B degradation

Piezocatalysis, based on the piezoelectric properties of catalysts, breaks down the barrier between mechanical energy and chemical energy. It describes the use of charges induced by piezoelectricity to assist typical chemical processes while harvesting various forms of mechanical green energy. The performance of piezocatalysis is predominantly governed by the piezoelectric properties of materials. The main aim of this work is to evaluate and analyze the potential of potassium doped sodium bismuth titanate Na0.5-xKxBi0.5TiO3 abbreviated as NKxBT (0, 0.15, 0.20, and 0.25), as a piezocatalyst in the degradation of the organic dye Rhodamine B RhB under ultrasonic vibration. The synthesis of NKxBT nanopowders was conducted using the sol-gel autocombustion method. Coupled structural analysis reveals the presence of an intermediate Morphotropic Phase Boundary (MPB, where two phases coexist) in the optimal NK15BT composition. The piezocatalytic degradation results showed a total piezo-degradation in only 90 min and a rate constant 8 times higher than the undoped NK0BT. The enhanced piezocatalytic activity results from a synergistic effect of MPB presence, reduced particle size, optimal bandgap and high lattice strain. The NK15BT sample also demonstrated good reusability and good mineralization.

cond-mat.mtrl-sci

Ferroelectric KNbO3 nanoplatelets for thermally driven pyrocatalytic hydrogen evolution and dye degradation

Day- and night-induced thermal cycling offers a promising route for harvesting ambient thermal energy to drive sustainable hydrogen production and pollutant degradation. Pyroelectric materials enable this process by converting temperature fluctuations into surface charges capable of promoting catalytic water splitting and advanced oxidation reactions. In this work, we demonstrate efficient pyrocatalytic hydrogen evolution and Rhodamine B (RhB) degradation using orthorhombic ferroelectric Potassium niobate (KNbO$_3$) nanoplatelets (KN-np). Under thermal cycling between 20 and 50 $^\circ$C, KN-np achieved a hydrogen yield of 680 $\mu$mol g$^{-1}$ after 30 thermal cycles, corresponding to an average hydrogen production rate of 22.67 $\mu$mol g$^{-1}$ per cycle. In addition, KN-np exhibited excellent pyrocatalytic activity toward RhB degradation, reaching 84% removal after only 16 thermal cycles with an apparent kinetic rate constant of 0.11 cycle$^{-1}$. The remarkable catalytic performance is attributed to the strong spontaneous polarization and excellent pyroelectric properties of the KNbO$_3$ nanoplatelets, which promote efficient charge generation and interfacial redox reactions. These findings highlight the potential of KNbO$_3$ nanostructures as efficient pyrocatalysts for clean hydrogen production and environmental remediation.

cond-mat.mtrl-sci