GaN　and　related　III-nitrides　have　attracted　significant　attention　due　to　their　excellent　performance　and　extensive　applications.　However,　the　substrates　for　epitaxial　growth　of　III-nitride　films　are　limited　to　a　few　options,　such　as　SiC,　Si,　and　sapphire,　which　suffer　from　significant　shortcomings　including　high　cost,　lattice　mismatch,　and　thermal　expansion　coefficient　mismatch.　In　this　study,　AlN　film　with　c-axis　orientation　was　deposited　on　a　2-inch　polycrystalline　Mo　substrate　using　reactive　magnetron　sputtering,　leveraging　the　advantages　of　Mo.　Additionally,　the　influence　of　a　two-dimensional　graphene　(Gr)　insertion　layer　on　the　epitaxy　of　III-nitrides　on　Mo　was　investigated.　The　introduction　of　Gr　slightly　reduced　the　grain　size　of　the　AlN　by　about　10　nm.　However,　the　Gr　induced　some　in-plane　tensile　strain　in　the　AlN　film,　which　compensated　the　compressive　strain　in　the　subsequently　grown　GaN,　resulting　in　a　more　undistorted　GaN　lattice　with　a　c-axis　strain　of　only　0.01　%.　Continuous　GaN　films　were　successfully　epitaxially　grown　on　the　sputtered　AlN　buffer　layers,　which　are　with　c-axis　preferred　orientation　and　ultraviolet　emission　at　∼3.36　eV.　The　grain　size　of　GaN　increased　by　about　5　nm　and　the　full　width　at　half　maximum　of　the　photoluminescence　spectra　also　decreased　by　about　2.5　nm　after　the　insertion　of　Gr.　Our　investigation　indicates　that　Mo　or　Gr/Mo　substrates　are　promising　candidates　for　the　heteroepitaxial　growth　of　GaN　films　using　sputtered　AlN　buffer　layers.　This　work　also　provides　a　valuable　strategy　for　low-cost　and　high-quality　heteroepitaxy　of　other　III-nitrides.　©　2025　Elsevier　B.V.