S-induced Phase Change Forming In 2 O 3 /In 2 S 3 Heterostructure for Photoelectrochemical Glucose Sensor.

In the past several decades, Photoelectrochemical (PEC) sensing still remains a great challenge to design highly-efficient semiconductor photocatalysts via a facile method. It is of much importance to design and synthesize various novel nanostructured sensing materials for further improving the response performance. Herein, we present an In 2 O 3 /In 2 S 3 heterostructure obtained by combining microwave assisted hydrothermal method with S-induced phase change, whose energy band and electronic structure could be adjusted by changing the S content. Combining theoretical calculation and spectroscopic techniques, the introduction of sulfur was proved to produce multifunctional interfaces, inducing the change of phase, oxygen vacancies and band gap, which accelerates the separation of photoexcited carriers and reduces their recombination, improving the electronic injection efficiency around the interface of In 2 O 3 /In 2 S 3 . As anticipated, an enhanced glucose response performance with a photocurrent of 0.6 mA cm -2 , a linear range of 0.1-1 mM and a detection limit as low as 14.5 μM has been achieved based on the In 2 O 3 /In 2 S 3 heterostructure, which is significant superior over its pure In 2 O 3 and S-doped In 2 O 3 counterparts. This efficient interfacial strategy may open a new route to manipulate the electrical structure, and energy band structure regulation of sensing material to improve the performance of photoelectrodes for PEC.