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Carbon black (CB) is commonly used to support Pt as an electrocatalyst in fuel cells. However, it is easily corroded in electrochemical reactions, such as in the oxygen reduction reaction (ORR), leading to catalyst degradation. In this paper, we report results of protecting the CB using an ultrathin 5 nm film of niobium oxide conformally coated on the CB using a new coating technique. Electrochemical test in ORR shows only a 1.7 % activity loss after 5000 cycles, demonstrating an excellent durability of the electrocatalyst. Compared to the electrocatalyst without niobium oxide coating, it shows a 25 mV improvement in half-wave potentials, indicative of a better kinetics. A positive shift in binding energy was found in Pt 4 f, implying electron delocalization has occurred when Pt is interfaced with the niobium oxide support. The activity enhancement is attributed to the electronic structure change in the electrocatalyst as a result of metal-support interactions.

Aluminosilicate zeolite nanoparticles were synthesized in a water-in-oil solvent and applied as an adsorbent for tetracycline (TC) removal from aqueous solutions. The large specific surface area at 495.8 m 2 g −1 confirms that the zeolite nanoparticles have mesopores. The zeolite nanoparticles show an excellent removal efficiency for TC, achieving over 97% in the pH range of 4.70−7.17. A fast adsorption kinetics was observed, reaching equilibrium in only 20 min following a pseudo-second-order kinetic model. The adsorption isotherm was found to follow the Langmuir model, with a maximum adsorption capacity of TC of 454.55 mg g −1 at pH 6.7 with no salt added. After 6 cycles of reuse, the removal efficiency of TC remained high at 90.3%. It was understood that the adsorption process is spontaneous and exothermic, with an activation energy of 37.94 kJ mol −1 . The high observed adsorption affinity is attributed to hydrogen bonding between TC and the hydroxyl groups on the zeolite nanoparticles and the formation of outer-sphere surface complexes. This study shows a new way to synthesize aluminosilicate zeolite nanoparticles that are an efficient and recyclable adsorbent for effective removal of TC from contaminated water.

Pt catalysts perform well in the oxygen reduction reaction (ORR), but they suffer weak bonding with carbon supports, leading to catalyst degradation. We introduce a fluffy titanium dioxide (TiO2) nanolayer with a very high specific surface area as support, made possible with a new condensed layer deposition technique. When Pt and SnO2 were incorporated in it as co-catalyst, a remarkable improvement in ORR onset potential was achieved at 930 mV vs RHE in sulfuric acids. The mass activity was 2.66 times that of Pt/C at 900 mV. The fluffy layer stabilized SnO2 and together, they enabled a pronounced ligand effect.