FeTiO3/TiO2 heterojunction for the electrocatalytic and photo-assisted electrocatalytic reduction of nitric oxide into ammonia

FeTiO3/TiO2 (FTTO) was successfully synthesized and applied for both electrocatalytic NO reduction reaction (eNORR) and photo-assisted eNORR. By introducing Fe into TiO2, a heterojunction of FeTiO3/TiO2 was constructed to enhance the electron transfer capability. The large specific surface area of FTTO can provide more active sites. In the eNORR, the FTTO achieved an NH3 yield of 2845.82 μg h−1 mg−1 at a voltage of −0.70 V (vs. RHE) in K2SO4 solution, which is 2.04 times that of unmodified TiO2. In the photo-assisted eNORR, the FTTO photoelectrode showed superior ammonia yield of 4259.97 μg h−1 mg−1, which is 11.74 times of that under exclusive illumination and 1.50 times for eNORR. The Zn–NO battery system, using FTTO as the positive electrode and Zn as the negative electrode, demonstrated an open-circuit voltage (OCV) of 2.15 V vs. Zn and an NH3 yield of 388.72 μg h−1 mg−1 at a current density of 5 mA cm−2.