AbstractMaximizing the utilization of photogenerated electrons and holes to drive the coupling reaction of hydrogen evolution with selective value‐added organic synthesis holds great potential for more efficient exploitation of solar energy. Herein, the interstitial boron‐doped CdS is synthesized by taking SiO2 as a template as well as the adsorption sites of boric acid, which contributes to the boron doping and induces the reinforced Cd─Se bonding for enhancing the interfacial interaction with co‐catalyst MoSe2. Thus, the interfacial Cd─Se bond with more electron localization provides rapid channels at the atomic level for accelerating the charge transfer with a lower energy barrier, achieving the efficient hydrogen evolution and high selectivity pyruvic acid synthesis concurrently. This work provides a new perspective in avoiding the use of sacrificial agents uneconomically and producing green hydrogen with high‐value‐added chemicals simultaneously.