Supported　metal　nanocatalysts　are　promising　candidates　for　heterogenous　photocatalysis　because　the　metal　nanoparticles　(e.g.,　Au,　Pt,　or　Pd)　loaded　on　the　semiconductor　surface　not　only　act　as　a　reductive　cocatalyst,　which　accelerates　the　kinetics　of　reactions　such　as　H+　reduction,　but　also　trap　the　photoelectrons,　which　allows　charge　separation.　Owing　to　these　unique　benefits,　supported　metal　photocatalysts　have　been　extensively　studied　for　green　H2　production　at　the　reductive　side　integrated　with　organic　selective　oxidation　at　the　oxidative　side　in　a　closed　photocatalytic　redox　cycle.　Imines　and　their　derivatives　are　important　chemicals　in　the　industrial　production　of　functional　polymers,　agrochemicals,　and　pharmaceuticals.　Recently,　imines　have　been　successfully　produced　via　the　photocatalytic　dehydrogenative　coupling　of　amines　over　supported　metal　nanocatalysts.　However,　owing　to　the　strong　adsorption　of　H　atoms　and　imines　on　the　metal　surface,　the　produced　imines　are　converted　to　secondary　amines　via　a　self-hydrogenation　process,　thus　greatly　decreasing　the　selectivity　toward　the　desired　imines.　Herein,　we　demonstrate　that　the　construction　of　an　ultrathin　carbon　layer　on　a　Pd/TiO2　photocatalyst　(Pd/TiO2@C)　via　the　thermal　annealing　of　self-assembled　polydopamine　layers　is　a　simple　yet　effective　strategy　to　address　this　issue.　Temperature-programmed　reduction　of　hydro　-oxygen　titration　and　cyclic　voltammetry　curves　for　Pd/TiO2　vs.　Pd/TiO2@C　indicate　that　the　conformable　coating　of　the　carbon　layer　on　the　catalyst　surface　facilitates　kinetic　control　of　H　atom　adsorption　on　the　supported　Pd　nanoparticles.　Furthermore,　in　situ　Fourier-transform　infrared　spectroscopy　demonstrates　that　the　conformably　coated　ultrathin　carbon　layer　also　decreases　the　adsorption　of　substrate　molecules　such　as　N-benzylidenebenzylamine　on　the　catalyst　surface,　which　weakens　their　interaction　with　the　supported　Pd　nanoparticles.　Thus,　the　construction　of　an　ultrathin　conformable　carbon　coating　on　Pd/TiO2　is　a　facile　strategy　to　kinetically　control　the　adsorption　behavior　of　H　atoms　and　imines　on　the　Pd　surface　during　photocatalytic　redox　reactions,　which　can　suppress　the　excessive　hydrogenation　of　imines　toward　selectivity　improvement.　In　addition,　owing　to　the　strong　electronic　interaction　between　the　Pd　nanoparticles　and　the　carbon　layer,　the　encapsulated　Pd　nanoparticles　retain　their　unique　catalytic　properties　toward　the　H2　evolution　reaction.　As　a　result,　Pd/TiO2@C　with　an　optimized　carbon　layer　thickness　facilitates　improved　photocatalytic　synthesis　of　imines,　with　conversion　and　selectivity　as　high　as　95%　and　99%,　respectively.　This　study　provides　an　effective　strategy　to　develop　high-performance　supported　metal　nanocatalysts　for　integrated　photocatalytic　systems　to　produce　H2　and　valuable　organic　chemicals.