The　development　of　efficient　photocatalyst　is　critical　for　the　practical　application　of　photocatalysis.　Herein,　Ti3C2　MXenes,　a　kind　of　2D-layered　material,　is　successfully　coupled　with　g-C3N4　sheets　under　ultrasound　irradiation.　A　series　of　characterization　methods　are　adopted　for　the　investigation　of　the　obtained　samples.　The　consequences　reflect　that　for　the　successful　formation　of　2D/2D　schottky　junction　and　a　new　Ti-N　bond　between　g-C3N4　and　Ti3C2.　Moreover,　photocatalytic　measurements　demonstrate　Ti3C2　MXenes　is　an　efficient　activator　for　g-C3N4　to　promote　its　photocatalytic　reactivity.　The　photocatalytic　fixation　of　N2　tests　manifest　that　the　optimized　sample　of　TC-CN-1　(g-C3N4　with　the　1　wt%　Ti3C2　MXene　loading)　shows　the　highest　generation　yield　of　NH4+　(601　umol　L-1·gcat-1·h-1),　which　is　3.64-fold　higher　than　that　of　pristine　g-C3N4　(203　umol　L-1·gcat-1·h-1).　Furthermore,　the　Ti3C2/g-C3N4　show　superior　photocatalytic　conversion　of　CO2　to　CO　or　CH4　yields　than　that　of　g-C3N4.　Besides,　the　photocatalytic　degradation　measurements　show　that　only　33.6%　of　levofloxacin　can　be　decomposed　by　pristine　g-C3N4,　while　the　removal　ratio　of　levofloxacin　reaches　72%　for　g-C3N4　with　1　wt%　loading　of　Ti3C2　MXene　under　visible　light　illumination　for　30　min.　The　photocatalytic　improvements　are　confirmed　to　benefit　from　the　faster　separation　of　photo-generated　electrons　and　holes,　higher　light　response　ability,　and　more　active　sites.　This　study　demonstrates　that　Ti3C2/g-C3N4　schottky　junction　is　a　promising　photocatalyst　for　the　photocatalytic　nitrogen　fixation,　and　antibiotics　degradation.　©　2021　Elsevier　B.V.