Robust route to H2O2 and H2 via intermediate water splitting enabled by capitalizing on minimum vanadium-doped piezocatalysts

H 2 O 2 is an environmentally friendly chemical for a wide range of water treatments. The industrial production of H 2 O 2 is an anthraquinone oxidation process, which, however, consumes extensive energy and produces pollution. Here we report a green and sustainable piezocatalytic intermediate water splitting process to simultaneously obtain H 2 O 2 and H 2 using single crystal vanadium (V)-doped NaNbO 3 (V-NaNbO 3 ) nanocubes as catalysts. The introduction of V improves the specific surface area and active sites of NaNbO 3 . Notably, V-NaNbO 3 piezocatalysts of 10 mg exhibit 3.1-fold higher piezocatalytic efficiency than the same catalysts of 50 mg, as more piezocatalysts lead to higher probability of aggregation. The aggregation causes reducing active sites and decreased built-in electric field due to the neutralization between different nano-catalysts. Remarkably, piezocatalytic H 2 O 2 and H 2 production rates of V-NaNbO 3 (10 mol%) nanocubes (102.6 and 346.2 µmol·g −1 ·h −1 , respectively) are increased by 2.2 and 4.6 times compared to the as-prepared pristine NaNbO 3 counterparts, respectively. This improved catalytic efficiency is attributed to the promoted piezo-response and more active sites of NaNbO 3 catalysts after V doping, as uncovered by piezo-response force microscopy (PFM) and density functional theory (DFT) simulation. More importantly, our DFT results illustrate that inducing V could reduce the dynamic barrier of water dissociation over NaNbO 3 , thus enhancing the yield of H 2 O 2 and H 2 . This facile yet robust piezocatalytic route using minimal amounts of catalysts to obtain H 2 O 2 and H 2 may stand out as a promising candidate for environmental applications and water splitting.