The paper reports a “green” method for hydrogen peroxide (H2O2) production and organic pollutants removal to solve the related environmental exacerbation. Herein, a novel two-dimensional (2D) nanocomposite of oxygen-doped graphitic carbon nitride nanosheets with sodium bismuth sulfide nanoribbons was prepared through hydrothermal treatment. Z-scheme-based charge-transfer dynamics could remarkably boost the spatial charge separation to promote the activation of molecular oxygen for H2O2 production and organic dyes degradation. As prepared, binary nanocomposite exhibited an ultra-high H2O2 production rate of 8.92 mmol L−1 following the one-step two-electron direct pathway, about 2-times higher than pristine oxygen-doped graphitic carbon nitride (4.95 mmol L−1). It was found that the degradation rate over prepared binary nanocomposite was reached almost 95% with the first-order kinetics. Moreover, a possible mechanism for the superior photocatalytic activity and nanostructure formation process was suggested based on the experimental results. This work is expected to open an avenue for developing novel visible-light-driven materials through nanostructure design.