Well-crystalline ZnO nanourchins were synthesized by facile hydrothermal process at low-temperature. X-rays diffraction patterns revealed that as-synthesized ZnO nanourchins exhibited good crystalline nature with typical hexagonal wurtzite phase. From the morphological characterization, the synthesized nanomaterials consisted of uniform spines and systematically arranged on a periphery and resembled to urchin like morphology. As-synthesized ZnO nanourchins were extensively utilized for photocatalyst and sensing devices. As-synthesized ZnO nanourchins as photocatalysts exhibited a good degradation rate of 98.5% within 80 min towards the degradation of acricline orange (AO) dye under UV light illumination. In sensing applications, the fabricated phenyl hydrazine chemical sensor based on ZnO nanourchin electrode accomplished high reproducible sensitivity of similar to 42.1 mu A mM(-1) cm(-2) along with a good limit of detection 78.6 mu M with correlation coefficient (R) of 0.98701. The enhanced sensing behavior and photodegradation of AO dye can be attributed to the large surface-to-volume ratio of as synthesized ZnO nanourchins, which provide large surface areas for the absorption of active oxygenated species. (C) 2014 Elsevier B.V. All rights reserved.