Light stimulation allows remote and spatiotemporally accurate operation that has been applied as effective, non-invasive means of therapeutic interventions. Here, visible light neural stimulation of graphitic carbon nitride (g-C3N4), an emerging photocatalyst with visible-light optoelectronic conversion, was for the first time investigated. Specifically, g-C3N4 was combined with graphene oxide (GO) in a 3D manner on the surfaces of electrospun polycaprolactone/gelatin (PG) fibers and functioned as a biocompatible interface for visible-light stimulating neuronal differentiation. The enhanced photocatalytic function of g-C3N4 was realized by spreading g-C3N4 on coated electrospun (PG) microfibers to improve both charge separation and surface area. Ascorbic acid (AA) was used in the cell culture medium, not only as a photo-excited hole scavenger, but also to mediate GO reduction to further improve the electrical conductivity. The successful coatings of g-C3N4, GO and AA-mediated GO reduction were confirmed using scanning electron microscopy (SEM), photoluminescence (PL), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Biocompatibility of g-C3N4 (0.01 to 0.9 mg/ml) to PC12 cells was confirmed by the Lactate Dehydrogenase (LDH) assay, live dead staining and colorimetric cell viability assay CCK-8. Under a bidaily, monochromatic light stimulation at a wavelength of 450 nm at 10mW/cm2, a 18.5-fold increase of neurite outgrowth of PC12 was found on g-C3N4 coated fibers; while AA reduced GO-gC3N4 hybrid brought a further 2.6-fold increase, suggesting its great potential as a visible-light neural stimulator that could optically enhance neural growth in a spatiotemporal-specific manner.