Luminescence Amplification at BiVO₄ Photoanodes by Photoinduced Electrochemiluminescence

Photoinduced electrochemiluminescence (PECL) combines semiconductor (SC) photoelectrochemistry with electrochemiluminescence (ECL). In PECL, the incident light is converted into a different wavelength by an electrochemical reaction at a SC photoelectrode and allows triggering of ECL at low potentials. This concept has been employed to design up-conversion systems. However, PECL strongly suffers from the photoelectrochemical instability of these low band gap SCs. Reported here for the first time is an original light-conversion strategy based on PECL of a luminol derivative (L-012) at BiVO₄ photoanodes in water. Incident light photoexcites simultaneously the L-012 fluorescence and the photoanode. However, the resulting signal is surpassed by the PECL emission. PECL can be induced at a potential as low as -0.4 V for several hours and can be employed to finely tune L-012 luminescence. This finding is promising for the design of new analytical strategies and light-addressable systems.