Spintronics in spintronic injection system-based energy harvesting devices demonstrate promising spin mobility and energy conversion efficiency. However, low spintronic population is a major challenge related to device performance, efficiency modulation, and the interface of heterostructures. For an effectively increasing spintronic population, a small polaron surface state acts as a spintronic filter, which converts the excited electrons of photosensitizers into spintronics. A high-performance spintronic injection system is also achieved in RuPc-coated ZrO2 nanoparticle water splitting cells. The charge mobility under the spin-down injection condition is as high as 4.17 x 10(14) m(2)/(V.s). Furthermore, compared with the required input power, only 61.79% of the theoretical power is required in our cases for water splitting and hydrogen evolution. The total energy conversion of our devices becomes as high as 194.98%. In this research, the small polaron surface state is provided to solve issues related to low functional power, high working temperatures, and the effect of the magnetic field from the spin Hall effect in spintronic injection systems and devices.