Production of high value-added solar fuels from sunlight and carbon dioxide (CO₂) have attracted much interest for achieving carbon neutrality, yet the current photocatalytic CO₂ reduction reaction (CRR) process still suffers from inactivation of inert molecules and severe charge recombination. Here, we report a versatile carbon dots (CDs)-triggered confined co-assembly strategy to integrate ultrafine tungsten trioxide (WO₃)/CDs quantum dots with graphitic carbon nitride (g-C₃N₄) for the fabrication of miniature g-C₃N₄/CDs/WO₃ Step-scheme (S-scheme) heterojunction. Without any sacrificial reagent, the optimal photocatalyst enables 99.5 % selectivity toward the production of CO, with the highest yield rate of 31.04 µmol‧g⁻¹‧h⁻¹ under the gas–solid phase reaction. In situ spectra investigation and density functional theory (DFT) calculations suggest that the bifunctional CDs not only trigger quantum-sized precise assembly of WO₃ nanocrystal on the surface of g-C₃N₄ matrix without aggregation, but also mediate the interfacial charge transportation. Moreover, the established S-scheme electron transfer pathway favor the rapid charge separation and directional transfer, thus ensuring the maximum utilization of photo-generated charge carriers for efficient photocatalytic CRR. This work provides a new tactic for rational design and synthesis CDs-mediated S-scheme heterojunction to harness solar energy into high value-added solar fuel.

_{利用阳光和二氧化碳(CO 2} )生产高附加值太阳能燃料对于实现碳中和引起了人们的广泛关注，但目前的光催化CO ₂还原反应(CRR)过程仍然存在惰性分子失活和严重的电荷重组的问题。在这里，我们报告了一种多功能碳点（CD）触发的限域共组装策略，将超细三氧化钨（WO ₃）/CDs量子点与石墨氮化碳（gC ₃ N ₄）集成，用于制造微型gC ₃ N ₄ /CDs/WO ₃阶梯式（S 式）异质结。在没有任何牺牲试剂的情况下，最佳光催化剂对CO的产生具有99.5%的选择性，在气固相反应下最高产率为31.04 µmol‧g ^-1 ‧h ^{-1 。}原位光谱研究和密度泛函理论（DFT）计算表明，双功能CD不仅可以在gC ₃ N ₄基质表面触发量子尺寸的WO ₃纳米晶体的精确组装而不聚集，而且还可以介导界面电荷传输。此外，所建立的S型电子转移路径有利于电荷的快速分离和定向转移，从而确保最大限度地利用光生电荷载流子，实现高效的光催化CRR。这项工作为合理设计和合成CDs介导的S型异质结以将太阳能转化为高附加值太阳能燃料提供了一种新策略。