We perform first-principles density function theory calculations to study the correlation between codoping forms and compensation mechanism in N-F pairs at ZnWO4 (0 1 0) surface. Our study considers substitutional as well as adsorptive and interstitial codoping forms at ZnWO4 (0 1 0) surface, and the results show that all the NsFs, NsFsd, NadFs, and NadFad codoping forms can passivate the partially occupied states formed in the corresponding monodoped systems to enhance the photoactivity of ZnWO4 (0 1 0) surface and decrease the transition energy of photoexcited electrons from the impurity levels to the conduction band minimum to low-energy area. There are four different compensation mechanisms in N-F pairs at ZnWO4 (0 1 0) surface, corresponding to the four codoping forms, and different compensation mechanisms in N-F pairs result in different effects on photoactivity of ZnWO4, such as the NadFad has little sense to photocatalytic process, due to the electrons only transferring between the N-ad-O-b pi* states. We expected that this knowledge could introduce some more general useful codoping concepts to the design of visible-light photocatalysts. (C) 2012 Elsevier B.V. All rights reserved.