A novel three-dimensional ordered nanoheterojunctions are fabricated and proposed in photocatalytic phenol degradation. CdS quantum dots (CdS QDs) are adopted as light harvesters for good visible light absorption capacity, and MoP inverse opals (MoP IO) are applied as cocatalysts for excellent electrical conductivity. The introduction of three-dimensional ordered MoP is beneficial to expose active sites and improve the light absorption efficiency of heterojunctions. Effects of pore sizes and deposited amounts of CdS quantum dots are investigated and optimal conditions are obtained. The optimal pseudo-first-order reaction rate constants of CdS/MoP IO is 2.912 x 10(-2) min(-1), which is 7.7 times higher than pure CdS QDs, indicating the heterojunctions effectively reduce the photocorrosion of CdS QDs. CdS/MoP IO exhibit efficient charger carriers separation and favorable stability, which might provide new insights into environmental remediation and solar energy conversion.