electrochemical cells for direct conversion of solar energy to electricity (or hydrogen) are one of the most sustainable solutions to meet the increasing worldwide energy demands. in this report, a novel and highly-efficient ternary heterojunction-structured Bi 4 o 7 /Bi 3.33 (Vo 4) 2 o 2 /Bi 46 V 8 o 89 photoelectrode is presented. it is demonstrated that the combination of an inversion layer, induced by holes (or electrons) at the interface of the semiconducting Bi 3.33 (Vo 4) 2 o 2 and Bi 46 V 8 o 89 components, and the rectifying contact between the Bi 4 o 7 and Bi 3.33 (Vo 4) 2 o 2 phases acting afterward as a conventional p-n junction, creates an adjustable virtual p-n-p or n-p-n junction due to self-polarization in the ion-conducting Bi 46 V 8 o 89 constituent. this design approach led to anodic and cathodic photocurrent densities of + 38.41 mA cm-2 (+ 0.76 V RHe) and-2.48 mA cm-2 (0 V RHe), respectively. Accordingly, first, this heterojunction can be used either as photoanode or as photocathode with great performance for artificial photosynthesis, noting, second, that the anodic response reveals exceptionally high: more than 300% superior to excellent values previously reported in the literature. Water splitting by photoelectrochemical cells (PECs) in the presence of light is a sustainable approach to directly convert solar energy into storable chemical energy (H 2 fuel) 1-5. Efforts to solve a number of deficiencies and to gain in performance have included modifying the electronic structure of the materials, constructing favorable surface structures with heterojunction, or controlling the morphology 6,7. The heterojunction concept is actually an excellent alternative for designing materials with improved photocatalytic properties 7 , because promoting a good separation and transport of the photogenerated charges 8,9. This is the case of bismuth vanadate-and bismuth oxide-based heterojunction systems like BiVO 4 /Bi 4 V 2 O 11 10