<p>The conversion of solar energy to facilitate the photocatalytic transformation of CO₂ into CH₄ addresses the energy shortage caused by reducing humans’ excessive dependence on fossil fuels and contributes substantially to the goal of carbon neutrality. However, there are still many limitations on the conversion of CO₂ to CH₄. In this work, a series of ZrO₂/Bi₁₉S₂₇Br₃ composite photocatalysts was prepared by the solvothermal method and applied to the methanation reaction of CO₂. Combining Bi₁₉S₂₇Br₃ with ZrO₂ forms a heterojunction with a strong coupling interface. This greatly enhanced the CO₂ adsorption performance of the 50-ZrO₂/Bi₁₉S₂₇Br₃ composite and promoted the effective separation of photogenerated electron–hole pairs. Without the addition of photosensitizers, the CH₄ selectivity of the 50-ZrO₂/Bi₁₉S₂₇Br₃ composite is approximately 63%, and the CH₄ generation rate is 18.04&#xa0;μmol/(g_cat·h), which is noticeably higher than that of ZrO₂ or Bi₁₉S₂₇Br₃. This research demonstrated enhanced photocatalytic CO₂ reduction efficiency using Bi₁₉S₂₇Br₃-based materials, providing a novel approach for the use of CO₂ resources.</p> Graphical Abstract <p></p>