Tuning structures of Pt shells on Pd nanocubes as neutral glucose oxidation catalysts and sensors

• Various Pt shell structures were synthesised on the surface of Pd NCs. • Pt surface facets impact significantly on the mechanism of neutral GOR. • GOR on the stellated Pd@Pt NCs with (211) facets occurs via a 12-electron patwahy. • Stellated Pd@Pt NCs are the best catalyst for sequential GOR. • Pd NCs with Pt corners having (210) and (950) facets enhance transient catalysis. Nanocrystals with high-indexed facets and low-coordinated atoms exhibit promising electrocatalytic activities. Herein, different Pt shell structures on the surface of Pd nanocubes (Pd@Pt NCs) were synthesised by varying the concentration of Pt precursors. The concave Pd@Pt NCs were used as electrocatalysts for neutral glucose oxidation reactions (GORs); the effect of Pt structure on the catalytic performance was studied. In sequential catalysis, stellated Pd@Pt NCs (Pd@Pt SNC) with (211) facets had an electron transfer number (N e ) of 12.69 and a specific activity of 4.69×10 -9 mol·g·m -2 , markedly higher than that of the other concave Pd@Pt NCs. In transient catalysis, Pd NCs with Pt-coated corners (Pd@Pt CNCC) containing (210) and (950) facets demonstrated a sensitivity of 11.06 μA·mM −1 ·cm −2 and a linear analysis range (2.4–10.6 mM). The high recoveries (98.80%–99.85%) and low relative standards (≤ 1.06%) in the serum sample corroborate the potential of Pd@Pt CNCC as an enzyme-free glucose sensor.