Photocatalytic　nitrogen　fixation　is　a　promising　green　strategy　for　ammonia　synthesis,　yet　the　high　activation　energy　for　nitrogen　is　the　significant　limitation　to　its　practical　application.　Herein,　a　novel　Fe-doped　WO3　photocatalyst　with　three　dimensional　macroporous　(3DOM)　structure　was　designed　and　prepared.　This　special　photocatalyst　not　only　provides　effective　adsorption　active　sites　to　enhance　the　chemisorption　and　activation　of　N2,　but　also　promotes　the　charge　separation　and　transfer　from　catalyst　to　nitrogen.　As　a　result,　the　optimized　5%　Fe-3DOM　WO3　sample　achieves　excellent　ammonia　production　rate　of　60　μmol　g−1h−1,　∼30　times　higher　than　that　of　pure　3DOM　WO3.　The　in-situ　DRIFTS　results　show　the　existence　of　several　intermediates　containing　N[sbnd]H　bonds　during　nitrogen　reduction.　Meanwhile,　the　density　functional　theory　calculation　results　show　that　the　presence　of　Fe　promotes　the　adsorption　and　activation　of　nitrogen,　and　the　reaction　pathway　is　biased　towards　the　alternate　hydrogenation　mechanism.　©　2022　Elsevier　Ltd